Repository: nipy/nipype

Issue:
`make specs` uses wrong version of nipype
`make specs` uses the installed version of nipype instead of the one in the CWD. Unless the developer has CWD in PYTHONPATH wrong tests will be generated.



Discussion:

Resolving patch:
diff --git a/tools/checkspecs.py b/tools/checkspecs.py
--- a/tools/checkspecs.py
+++ b/tools/checkspecs.py
@@ -155,6 +155,22 @@ def _parse_lines(self, linesource, module):
         classes.sort()
         return functions, classes
 
+    @classmethod
+    def _normalize_repr(cls, value):
+        if isinstance(value, list):
+            return '[{}]'.format(', '.join(map(cls._normalize_repr, value)))
+        if isinstance(value, tuple):
+            if len(value) == 1:
+                return '({},)'.format(cls._normalize_repr(value[0]))
+            return '({})'.format(', '.join(map(cls._normalize_repr, value)))
+        if isinstance(value, (str, bytes)):
+            value = repr(value)
+            if value[0] not in ('"', "'"):
+                value = value[1:]
+        else:
+            value = repr(value)
+        return value
+
     def test_specs(self, uri):
         """Check input and output specs in an uri
 
@@ -206,6 +222,7 @@ def test_specs(self, uri):
             if not os.path.exists(nonautotest):
                 with open(testfile, 'wt') as fp:
                     cmd = ['# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT',
+                           'from __future__ import unicode_literals',
                            'from ..%s import %s' % (uri.split('.')[-1], c),
                            '']
                     cmd.append('\ndef test_%s_inputs():' % c)
@@ -215,14 +232,7 @@ def test_specs(self, uri):
                         for key, value in sorted(trait.__dict__.items()):
                             if key in in_built or key == 'desc':
                                 continue
-                            if isinstance(value, (str, bytes)):
-                                quote = "'"
-                                if "'" in value:
-                                    quote = '"'
-                                input_fields += "%s=%s%s%s,\n    " % (key, quote,
-                                                                      value, quote)
-                            else:
-                                input_fields += "%s=%s,\n    " % (key, value)
+                            input_fields += "%s=%s,\n    " % (key, self._normalize_repr(value))
                         input_fields += '),\n    '
                     cmd += ['    input_map = dict(%s)' % input_fields]
                     cmd += ['    inputs = %s.input_spec()' % c]
@@ -259,14 +269,7 @@ def test_specs(self, uri):
                         for key, value in sorted(trait.__dict__.items()):
                             if key in in_built or key == 'desc':
                                 continue
-                            if isinstance(value, (str, bytes)):
-                                quote = "'"
-                                if "'" in value:
-                                    quote = '"'
-                                input_fields += "%s=%s%s%s,\n    " % (key, quote,
-                                                                      value, quote)
-                            else:
-                                input_fields += "%s=%s,\n    " % (key, value)
+                            input_fields += "%s=%s,\n    " % (key, self._normalize_repr(value))
                         input_fields += '),\n    '
                     cmd += ['    output_map = dict(%s)' % input_fields]
                     cmd += ['    outputs = %s.output_spec()' % c]


Test patch:
diff --git a/nipype/algorithms/tests/test_auto_ACompCor.py b/nipype/algorithms/tests/test_auto_ACompCor.py
--- a/nipype/algorithms/tests/test_auto_ACompCor.py
+++ b/nipype/algorithms/tests/test_auto_ACompCor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..confounds import ACompCor
 
 
diff --git a/nipype/algorithms/tests/test_auto_AddCSVColumn.py b/nipype/algorithms/tests/test_auto_AddCSVColumn.py
--- a/nipype/algorithms/tests/test_auto_AddCSVColumn.py
+++ b/nipype/algorithms/tests/test_auto_AddCSVColumn.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import AddCSVColumn
 
 
diff --git a/nipype/algorithms/tests/test_auto_AddCSVRow.py b/nipype/algorithms/tests/test_auto_AddCSVRow.py
--- a/nipype/algorithms/tests/test_auto_AddCSVRow.py
+++ b/nipype/algorithms/tests/test_auto_AddCSVRow.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import AddCSVRow
 
 
diff --git a/nipype/algorithms/tests/test_auto_AddNoise.py b/nipype/algorithms/tests/test_auto_AddNoise.py
--- a/nipype/algorithms/tests/test_auto_AddNoise.py
+++ b/nipype/algorithms/tests/test_auto_AddNoise.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import AddNoise
 
 
diff --git a/nipype/algorithms/tests/test_auto_ArtifactDetect.py b/nipype/algorithms/tests/test_auto_ArtifactDetect.py
--- a/nipype/algorithms/tests/test_auto_ArtifactDetect.py
+++ b/nipype/algorithms/tests/test_auto_ArtifactDetect.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..rapidart import ArtifactDetect
 
 
@@ -16,7 +17,7 @@ def test_ArtifactDetect_inputs():
     mask_type=dict(mandatory=True,
     ),
     norm_threshold=dict(mandatory=True,
-    xor=[u'rotation_threshold', u'translation_threshold'],
+    xor=['rotation_threshold', 'translation_threshold'],
     ),
     parameter_source=dict(mandatory=True,
     ),
@@ -27,18 +28,18 @@ def test_ArtifactDetect_inputs():
     realignment_parameters=dict(mandatory=True,
     ),
     rotation_threshold=dict(mandatory=True,
-    xor=[u'norm_threshold'],
+    xor=['norm_threshold'],
     ),
     save_plot=dict(usedefault=True,
     ),
     translation_threshold=dict(mandatory=True,
-    xor=[u'norm_threshold'],
+    xor=['norm_threshold'],
     ),
     use_differences=dict(maxlen=2,
     minlen=2,
     usedefault=True,
     ),
-    use_norm=dict(requires=[u'norm_threshold'],
+    use_norm=dict(requires=['norm_threshold'],
     usedefault=True,
     ),
     zintensity_threshold=dict(mandatory=True,
diff --git a/nipype/algorithms/tests/test_auto_CalculateNormalizedMoments.py b/nipype/algorithms/tests/test_auto_CalculateNormalizedMoments.py
--- a/nipype/algorithms/tests/test_auto_CalculateNormalizedMoments.py
+++ b/nipype/algorithms/tests/test_auto_CalculateNormalizedMoments.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import CalculateNormalizedMoments
 
 
diff --git a/nipype/algorithms/tests/test_auto_CompCor.py b/nipype/algorithms/tests/test_auto_CompCor.py
new file mode 100644
--- /dev/null
+++ b/nipype/algorithms/tests/test_auto_CompCor.py
@@ -0,0 +1,37 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..confounds import CompCor
+
+
+def test_CompCor_inputs():
+    input_map = dict(components_file=dict(usedefault=True,
+    ),
+    header=dict(),
+    ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    mask_file=dict(),
+    num_components=dict(usedefault=True,
+    ),
+    realigned_file=dict(mandatory=True,
+    ),
+    regress_poly_degree=dict(usedefault=True,
+    ),
+    use_regress_poly=dict(usedefault=True,
+    ),
+    )
+    inputs = CompCor.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_CompCor_outputs():
+    output_map = dict(components_file=dict(),
+    )
+    outputs = CompCor.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/algorithms/tests/test_auto_ComputeDVARS.py b/nipype/algorithms/tests/test_auto_ComputeDVARS.py
--- a/nipype/algorithms/tests/test_auto_ComputeDVARS.py
+++ b/nipype/algorithms/tests/test_auto_ComputeDVARS.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..confounds import ComputeDVARS
 
 
diff --git a/nipype/algorithms/tests/test_auto_ComputeMeshWarp.py b/nipype/algorithms/tests/test_auto_ComputeMeshWarp.py
--- a/nipype/algorithms/tests/test_auto_ComputeMeshWarp.py
+++ b/nipype/algorithms/tests/test_auto_ComputeMeshWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..mesh import ComputeMeshWarp
 
 
diff --git a/nipype/algorithms/tests/test_auto_CreateNifti.py b/nipype/algorithms/tests/test_auto_CreateNifti.py
--- a/nipype/algorithms/tests/test_auto_CreateNifti.py
+++ b/nipype/algorithms/tests/test_auto_CreateNifti.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import CreateNifti
 
 
diff --git a/nipype/algorithms/tests/test_auto_Distance.py b/nipype/algorithms/tests/test_auto_Distance.py
--- a/nipype/algorithms/tests/test_auto_Distance.py
+++ b/nipype/algorithms/tests/test_auto_Distance.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import Distance
 
 
diff --git a/nipype/algorithms/tests/test_auto_ErrorMap.py b/nipype/algorithms/tests/test_auto_ErrorMap.py
new file mode 100644
--- /dev/null
+++ b/nipype/algorithms/tests/test_auto_ErrorMap.py
@@ -0,0 +1,35 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..metrics import ErrorMap
+
+
+def test_ErrorMap_inputs():
+    input_map = dict(ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    in_ref=dict(mandatory=True,
+    ),
+    in_tst=dict(mandatory=True,
+    ),
+    mask=dict(),
+    metric=dict(mandatory=True,
+    usedefault=True,
+    ),
+    out_map=dict(),
+    )
+    inputs = ErrorMap.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_ErrorMap_outputs():
+    output_map = dict(distance=dict(),
+    out_map=dict(),
+    )
+    outputs = ErrorMap.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/algorithms/tests/test_auto_FramewiseDisplacement.py b/nipype/algorithms/tests/test_auto_FramewiseDisplacement.py
--- a/nipype/algorithms/tests/test_auto_FramewiseDisplacement.py
+++ b/nipype/algorithms/tests/test_auto_FramewiseDisplacement.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..confounds import FramewiseDisplacement
 
 
diff --git a/nipype/algorithms/tests/test_auto_FuzzyOverlap.py b/nipype/algorithms/tests/test_auto_FuzzyOverlap.py
--- a/nipype/algorithms/tests/test_auto_FuzzyOverlap.py
+++ b/nipype/algorithms/tests/test_auto_FuzzyOverlap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import FuzzyOverlap
 
 
diff --git a/nipype/algorithms/tests/test_auto_Gunzip.py b/nipype/algorithms/tests/test_auto_Gunzip.py
--- a/nipype/algorithms/tests/test_auto_Gunzip.py
+++ b/nipype/algorithms/tests/test_auto_Gunzip.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import Gunzip
 
 
diff --git a/nipype/algorithms/tests/test_auto_ICC.py b/nipype/algorithms/tests/test_auto_ICC.py
--- a/nipype/algorithms/tests/test_auto_ICC.py
+++ b/nipype/algorithms/tests/test_auto_ICC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..icc import ICC
 
 
diff --git a/nipype/algorithms/tests/test_auto_Matlab2CSV.py b/nipype/algorithms/tests/test_auto_Matlab2CSV.py
--- a/nipype/algorithms/tests/test_auto_Matlab2CSV.py
+++ b/nipype/algorithms/tests/test_auto_Matlab2CSV.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import Matlab2CSV
 
 
diff --git a/nipype/algorithms/tests/test_auto_MergeCSVFiles.py b/nipype/algorithms/tests/test_auto_MergeCSVFiles.py
--- a/nipype/algorithms/tests/test_auto_MergeCSVFiles.py
+++ b/nipype/algorithms/tests/test_auto_MergeCSVFiles.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import MergeCSVFiles
 
 
diff --git a/nipype/algorithms/tests/test_auto_MergeROIs.py b/nipype/algorithms/tests/test_auto_MergeROIs.py
--- a/nipype/algorithms/tests/test_auto_MergeROIs.py
+++ b/nipype/algorithms/tests/test_auto_MergeROIs.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import MergeROIs
 
 
diff --git a/nipype/algorithms/tests/test_auto_MeshWarpMaths.py b/nipype/algorithms/tests/test_auto_MeshWarpMaths.py
--- a/nipype/algorithms/tests/test_auto_MeshWarpMaths.py
+++ b/nipype/algorithms/tests/test_auto_MeshWarpMaths.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..mesh import MeshWarpMaths
 
 
diff --git a/nipype/algorithms/tests/test_auto_ModifyAffine.py b/nipype/algorithms/tests/test_auto_ModifyAffine.py
--- a/nipype/algorithms/tests/test_auto_ModifyAffine.py
+++ b/nipype/algorithms/tests/test_auto_ModifyAffine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import ModifyAffine
 
 
diff --git a/nipype/algorithms/tests/test_auto_NormalizeProbabilityMapSet.py b/nipype/algorithms/tests/test_auto_NormalizeProbabilityMapSet.py
--- a/nipype/algorithms/tests/test_auto_NormalizeProbabilityMapSet.py
+++ b/nipype/algorithms/tests/test_auto_NormalizeProbabilityMapSet.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import NormalizeProbabilityMapSet
 
 
diff --git a/nipype/algorithms/tests/test_auto_Overlap.py b/nipype/algorithms/tests/test_auto_Overlap.py
new file mode 100644
--- /dev/null
+++ b/nipype/algorithms/tests/test_auto_Overlap.py
@@ -0,0 +1,47 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..misc import Overlap
+
+
+def test_Overlap_inputs():
+    input_map = dict(bg_overlap=dict(mandatory=True,
+    usedefault=True,
+    ),
+    ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    mask_volume=dict(),
+    out_file=dict(usedefault=True,
+    ),
+    vol_units=dict(mandatory=True,
+    usedefault=True,
+    ),
+    volume1=dict(mandatory=True,
+    ),
+    volume2=dict(mandatory=True,
+    ),
+    weighting=dict(usedefault=True,
+    ),
+    )
+    inputs = Overlap.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_Overlap_outputs():
+    output_map = dict(dice=dict(),
+    diff_file=dict(),
+    jaccard=dict(),
+    labels=dict(),
+    roi_di=dict(),
+    roi_ji=dict(),
+    roi_voldiff=dict(),
+    volume_difference=dict(),
+    )
+    outputs = Overlap.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/algorithms/tests/test_auto_P2PDistance.py b/nipype/algorithms/tests/test_auto_P2PDistance.py
--- a/nipype/algorithms/tests/test_auto_P2PDistance.py
+++ b/nipype/algorithms/tests/test_auto_P2PDistance.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..mesh import P2PDistance
 
 
diff --git a/nipype/algorithms/tests/test_auto_PickAtlas.py b/nipype/algorithms/tests/test_auto_PickAtlas.py
--- a/nipype/algorithms/tests/test_auto_PickAtlas.py
+++ b/nipype/algorithms/tests/test_auto_PickAtlas.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import PickAtlas
 
 
diff --git a/nipype/algorithms/tests/test_auto_Similarity.py b/nipype/algorithms/tests/test_auto_Similarity.py
--- a/nipype/algorithms/tests/test_auto_Similarity.py
+++ b/nipype/algorithms/tests/test_auto_Similarity.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..metrics import Similarity
 
 
diff --git a/nipype/algorithms/tests/test_auto_SimpleThreshold.py b/nipype/algorithms/tests/test_auto_SimpleThreshold.py
--- a/nipype/algorithms/tests/test_auto_SimpleThreshold.py
+++ b/nipype/algorithms/tests/test_auto_SimpleThreshold.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import SimpleThreshold
 
 
diff --git a/nipype/algorithms/tests/test_auto_SpecifyModel.py b/nipype/algorithms/tests/test_auto_SpecifyModel.py
--- a/nipype/algorithms/tests/test_auto_SpecifyModel.py
+++ b/nipype/algorithms/tests/test_auto_SpecifyModel.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..modelgen import SpecifyModel
 
 
 def test_SpecifyModel_inputs():
     input_map = dict(event_files=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     functional_runs=dict(copyfile=False,
     mandatory=True,
@@ -21,7 +22,7 @@ def test_SpecifyModel_inputs():
     realignment_parameters=dict(copyfile=False,
     ),
     subject_info=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     time_repetition=dict(mandatory=True,
     ),
diff --git a/nipype/algorithms/tests/test_auto_SpecifySPMModel.py b/nipype/algorithms/tests/test_auto_SpecifySPMModel.py
--- a/nipype/algorithms/tests/test_auto_SpecifySPMModel.py
+++ b/nipype/algorithms/tests/test_auto_SpecifySPMModel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..modelgen import SpecifySPMModel
 
 
@@ -6,7 +7,7 @@ def test_SpecifySPMModel_inputs():
     input_map = dict(concatenate_runs=dict(usedefault=True,
     ),
     event_files=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     functional_runs=dict(copyfile=False,
     mandatory=True,
@@ -25,7 +26,7 @@ def test_SpecifySPMModel_inputs():
     realignment_parameters=dict(copyfile=False,
     ),
     subject_info=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     time_repetition=dict(mandatory=True,
     ),
diff --git a/nipype/algorithms/tests/test_auto_SpecifySparseModel.py b/nipype/algorithms/tests/test_auto_SpecifySparseModel.py
--- a/nipype/algorithms/tests/test_auto_SpecifySparseModel.py
+++ b/nipype/algorithms/tests/test_auto_SpecifySparseModel.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..modelgen import SpecifySparseModel
 
 
 def test_SpecifySparseModel_inputs():
     input_map = dict(event_files=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     functional_runs=dict(copyfile=False,
     mandatory=True,
@@ -29,13 +30,13 @@ def test_SpecifySparseModel_inputs():
     stimuli_as_impulses=dict(usedefault=True,
     ),
     subject_info=dict(mandatory=True,
-    xor=[u'subject_info', u'event_files'],
+    xor=['subject_info', 'event_files'],
     ),
     time_acquisition=dict(mandatory=True,
     ),
     time_repetition=dict(mandatory=True,
     ),
-    use_temporal_deriv=dict(requires=[u'model_hrf'],
+    use_temporal_deriv=dict(requires=['model_hrf'],
     ),
     volumes_in_cluster=dict(usedefault=True,
     ),
diff --git a/nipype/algorithms/tests/test_auto_SplitROIs.py b/nipype/algorithms/tests/test_auto_SplitROIs.py
--- a/nipype/algorithms/tests/test_auto_SplitROIs.py
+++ b/nipype/algorithms/tests/test_auto_SplitROIs.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..misc import SplitROIs
 
 
diff --git a/nipype/algorithms/tests/test_auto_StimulusCorrelation.py b/nipype/algorithms/tests/test_auto_StimulusCorrelation.py
--- a/nipype/algorithms/tests/test_auto_StimulusCorrelation.py
+++ b/nipype/algorithms/tests/test_auto_StimulusCorrelation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..rapidart import StimulusCorrelation
 
 
diff --git a/nipype/algorithms/tests/test_auto_TCompCor.py b/nipype/algorithms/tests/test_auto_TCompCor.py
--- a/nipype/algorithms/tests/test_auto_TCompCor.py
+++ b/nipype/algorithms/tests/test_auto_TCompCor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..confounds import TCompCor
 
 
diff --git a/nipype/algorithms/tests/test_auto_TSNR.py b/nipype/algorithms/tests/test_auto_TSNR.py
new file mode 100644
--- /dev/null
+++ b/nipype/algorithms/tests/test_auto_TSNR.py
@@ -0,0 +1,43 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..misc import TSNR
+
+
+def test_TSNR_inputs():
+    input_map = dict(detrended_file=dict(hash_files=False,
+    usedefault=True,
+    ),
+    ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    in_file=dict(mandatory=True,
+    ),
+    mean_file=dict(hash_files=False,
+    usedefault=True,
+    ),
+    regress_poly=dict(),
+    stddev_file=dict(hash_files=False,
+    usedefault=True,
+    ),
+    tsnr_file=dict(hash_files=False,
+    usedefault=True,
+    ),
+    )
+    inputs = TSNR.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_TSNR_outputs():
+    output_map = dict(detrended_file=dict(),
+    mean_file=dict(),
+    stddev_file=dict(),
+    tsnr_file=dict(),
+    )
+    outputs = TSNR.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/algorithms/tests/test_auto_TVTKBaseInterface.py b/nipype/algorithms/tests/test_auto_TVTKBaseInterface.py
--- a/nipype/algorithms/tests/test_auto_TVTKBaseInterface.py
+++ b/nipype/algorithms/tests/test_auto_TVTKBaseInterface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..mesh import TVTKBaseInterface
 
 
diff --git a/nipype/algorithms/tests/test_auto_WarpPoints.py b/nipype/algorithms/tests/test_auto_WarpPoints.py
--- a/nipype/algorithms/tests/test_auto_WarpPoints.py
+++ b/nipype/algorithms/tests/test_auto_WarpPoints.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..mesh import WarpPoints
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_AFNICommand.py b/nipype/interfaces/afni/tests/test_auto_AFNICommand.py
--- a/nipype/interfaces/afni/tests/test_auto_AFNICommand.py
+++ b/nipype/interfaces/afni/tests/test_auto_AFNICommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import AFNICommand
 
 
@@ -12,7 +13,7 @@ def test_AFNICommand_inputs():
     usedefault=True,
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_AFNICommandBase.py b/nipype/interfaces/afni/tests/test_auto_AFNICommandBase.py
--- a/nipype/interfaces/afni/tests/test_auto_AFNICommandBase.py
+++ b/nipype/interfaces/afni/tests/test_auto_AFNICommandBase.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import AFNICommandBase
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_AFNItoNIFTI.py b/nipype/interfaces/afni/tests/test_auto_AFNItoNIFTI.py
--- a/nipype/interfaces/afni/tests/test_auto_AFNItoNIFTI.py
+++ b/nipype/interfaces/afni/tests/test_auto_AFNItoNIFTI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import AFNItoNIFTI
 
 
@@ -19,10 +20,10 @@ def test_AFNItoNIFTI_inputs():
     position=-1,
     ),
     newid=dict(argstr='-newid',
-    xor=[u'oldid'],
+    xor=['oldid'],
     ),
     oldid=dict(argstr='-oldid',
-    xor=[u'newid'],
+    xor=['newid'],
     ),
     out_file=dict(argstr='-prefix %s',
     hash_files=False,
diff --git a/nipype/interfaces/afni/tests/test_auto_Allineate.py b/nipype/interfaces/afni/tests/test_auto_Allineate.py
--- a/nipype/interfaces/afni/tests/test_auto_Allineate.py
+++ b/nipype/interfaces/afni/tests/test_auto_Allineate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Allineate
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_AutoTcorrelate.py b/nipype/interfaces/afni/tests/test_auto_AutoTcorrelate.py
--- a/nipype/interfaces/afni/tests/test_auto_AutoTcorrelate.py
+++ b/nipype/interfaces/afni/tests/test_auto_AutoTcorrelate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import AutoTcorrelate
 
 
@@ -21,10 +22,10 @@ def test_AutoTcorrelate_inputs():
     mask=dict(argstr='-mask %s',
     ),
     mask_only_targets=dict(argstr='-mask_only_targets',
-    xor=[u'mask_source'],
+    xor=['mask_source'],
     ),
     mask_source=dict(argstr='-mask_source %s',
-    xor=[u'mask_only_targets'],
+    xor=['mask_only_targets'],
     ),
     out_file=dict(argstr='-prefix %s',
     name_source='in_file',
diff --git a/nipype/interfaces/afni/tests/test_auto_Autobox.py b/nipype/interfaces/afni/tests/test_auto_Autobox.py
--- a/nipype/interfaces/afni/tests/test_auto_Autobox.py
+++ b/nipype/interfaces/afni/tests/test_auto_Autobox.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Autobox
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Automask.py b/nipype/interfaces/afni/tests/test_auto_Automask.py
--- a/nipype/interfaces/afni/tests/test_auto_Automask.py
+++ b/nipype/interfaces/afni/tests/test_auto_Automask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Automask
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Bandpass.py b/nipype/interfaces/afni/tests/test_auto_Bandpass.py
--- a/nipype/interfaces/afni/tests/test_auto_Bandpass.py
+++ b/nipype/interfaces/afni/tests/test_auto_Bandpass.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Bandpass
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_BlurInMask.py b/nipype/interfaces/afni/tests/test_auto_BlurInMask.py
--- a/nipype/interfaces/afni/tests/test_auto_BlurInMask.py
+++ b/nipype/interfaces/afni/tests/test_auto_BlurInMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import BlurInMask
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_BlurToFWHM.py b/nipype/interfaces/afni/tests/test_auto_BlurToFWHM.py
--- a/nipype/interfaces/afni/tests/test_auto_BlurToFWHM.py
+++ b/nipype/interfaces/afni/tests/test_auto_BlurToFWHM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import BlurToFWHM
 
 
@@ -25,7 +26,7 @@ def test_BlurToFWHM_inputs():
     mask=dict(argstr='-blurmaster %s',
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_BrickStat.py b/nipype/interfaces/afni/tests/test_auto_BrickStat.py
--- a/nipype/interfaces/afni/tests/test_auto_BrickStat.py
+++ b/nipype/interfaces/afni/tests/test_auto_BrickStat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import BrickStat
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Calc.py b/nipype/interfaces/afni/tests/test_auto_Calc.py
--- a/nipype/interfaces/afni/tests/test_auto_Calc.py
+++ b/nipype/interfaces/afni/tests/test_auto_Calc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Calc
 
 
@@ -33,9 +34,9 @@ def test_Calc_inputs():
     ),
     outputtype=dict(),
     single_idx=dict(),
-    start_idx=dict(requires=[u'stop_idx'],
+    start_idx=dict(requires=['stop_idx'],
     ),
-    stop_idx=dict(requires=[u'start_idx'],
+    stop_idx=dict(requires=['start_idx'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_ClipLevel.py b/nipype/interfaces/afni/tests/test_auto_ClipLevel.py
--- a/nipype/interfaces/afni/tests/test_auto_ClipLevel.py
+++ b/nipype/interfaces/afni/tests/test_auto_ClipLevel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ClipLevel
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Copy.py b/nipype/interfaces/afni/tests/test_auto_Copy.py
--- a/nipype/interfaces/afni/tests/test_auto_Copy.py
+++ b/nipype/interfaces/afni/tests/test_auto_Copy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Copy
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_DegreeCentrality.py b/nipype/interfaces/afni/tests/test_auto_DegreeCentrality.py
--- a/nipype/interfaces/afni/tests/test_auto_DegreeCentrality.py
+++ b/nipype/interfaces/afni/tests/test_auto_DegreeCentrality.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import DegreeCentrality
 
 
@@ -25,7 +26,7 @@ def test_DegreeCentrality_inputs():
     oned_file=dict(argstr='-out1D %s',
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_Despike.py b/nipype/interfaces/afni/tests/test_auto_Despike.py
--- a/nipype/interfaces/afni/tests/test_auto_Despike.py
+++ b/nipype/interfaces/afni/tests/test_auto_Despike.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Despike
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Detrend.py b/nipype/interfaces/afni/tests/test_auto_Detrend.py
--- a/nipype/interfaces/afni/tests/test_auto_Detrend.py
+++ b/nipype/interfaces/afni/tests/test_auto_Detrend.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Detrend
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_ECM.py b/nipype/interfaces/afni/tests/test_auto_ECM.py
--- a/nipype/interfaces/afni/tests/test_auto_ECM.py
+++ b/nipype/interfaces/afni/tests/test_auto_ECM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ECM
 
 
@@ -33,7 +34,7 @@ def test_ECM_inputs():
     memory=dict(argstr='-memory %f',
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_Eval.py b/nipype/interfaces/afni/tests/test_auto_Eval.py
--- a/nipype/interfaces/afni/tests/test_auto_Eval.py
+++ b/nipype/interfaces/afni/tests/test_auto_Eval.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Eval
 
 
@@ -35,9 +36,9 @@ def test_Eval_inputs():
     ),
     outputtype=dict(),
     single_idx=dict(),
-    start_idx=dict(requires=[u'stop_idx'],
+    start_idx=dict(requires=['stop_idx'],
     ),
-    stop_idx=dict(requires=[u'start_idx'],
+    stop_idx=dict(requires=['start_idx'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_FWHMx.py b/nipype/interfaces/afni/tests/test_auto_FWHMx.py
--- a/nipype/interfaces/afni/tests/test_auto_FWHMx.py
+++ b/nipype/interfaces/afni/tests/test_auto_FWHMx.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import FWHMx
 
 
@@ -9,7 +10,7 @@ def test_FWHMx_inputs():
     args=dict(argstr='%s',
     ),
     arith=dict(argstr='-arith',
-    xor=[u'geom'],
+    xor=['geom'],
     ),
     automask=dict(argstr='-automask',
     usedefault=True,
@@ -19,17 +20,17 @@ def test_FWHMx_inputs():
     compat=dict(argstr='-compat',
     ),
     demed=dict(argstr='-demed',
-    xor=[u'detrend'],
+    xor=['detrend'],
     ),
     detrend=dict(argstr='-detrend',
     usedefault=True,
-    xor=[u'demed'],
+    xor=['demed'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
     ),
     geom=dict(argstr='-geom',
-    xor=[u'arith'],
+    xor=['arith'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/afni/tests/test_auto_Fim.py b/nipype/interfaces/afni/tests/test_auto_Fim.py
--- a/nipype/interfaces/afni/tests/test_auto_Fim.py
+++ b/nipype/interfaces/afni/tests/test_auto_Fim.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Fim
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Fourier.py b/nipype/interfaces/afni/tests/test_auto_Fourier.py
--- a/nipype/interfaces/afni/tests/test_auto_Fourier.py
+++ b/nipype/interfaces/afni/tests/test_auto_Fourier.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Fourier
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Hist.py b/nipype/interfaces/afni/tests/test_auto_Hist.py
--- a/nipype/interfaces/afni/tests/test_auto_Hist.py
+++ b/nipype/interfaces/afni/tests/test_auto_Hist.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Hist
 
 
@@ -28,7 +29,7 @@ def test_Hist_inputs():
     ),
     out_file=dict(argstr='-prefix %s',
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_hist',
     ),
     out_show=dict(argstr='> %s',
diff --git a/nipype/interfaces/afni/tests/test_auto_LFCD.py b/nipype/interfaces/afni/tests/test_auto_LFCD.py
--- a/nipype/interfaces/afni/tests/test_auto_LFCD.py
+++ b/nipype/interfaces/afni/tests/test_auto_LFCD.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import LFCD
 
 
@@ -23,7 +24,7 @@ def test_LFCD_inputs():
     mask=dict(argstr='-mask %s',
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_MaskTool.py b/nipype/interfaces/afni/tests/test_auto_MaskTool.py
--- a/nipype/interfaces/afni/tests/test_auto_MaskTool.py
+++ b/nipype/interfaces/afni/tests/test_auto_MaskTool.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MaskTool
 
 
@@ -18,7 +19,7 @@ def test_MaskTool_inputs():
     usedefault=True,
     ),
     fill_dirs=dict(argstr='-fill_dirs %s',
-    requires=[u'fill_holes'],
+    requires=['fill_holes'],
     ),
     fill_holes=dict(argstr='-fill_holes',
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_Maskave.py b/nipype/interfaces/afni/tests/test_auto_Maskave.py
--- a/nipype/interfaces/afni/tests/test_auto_Maskave.py
+++ b/nipype/interfaces/afni/tests/test_auto_Maskave.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Maskave
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Means.py b/nipype/interfaces/afni/tests/test_auto_Means.py
--- a/nipype/interfaces/afni/tests/test_auto_Means.py
+++ b/nipype/interfaces/afni/tests/test_auto_Means.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Means
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Merge.py b/nipype/interfaces/afni/tests/test_auto_Merge.py
--- a/nipype/interfaces/afni/tests/test_auto_Merge.py
+++ b/nipype/interfaces/afni/tests/test_auto_Merge.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Merge
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Notes.py b/nipype/interfaces/afni/tests/test_auto_Notes.py
--- a/nipype/interfaces/afni/tests/test_auto_Notes.py
+++ b/nipype/interfaces/afni/tests/test_auto_Notes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Notes
 
 
@@ -6,7 +7,7 @@ def test_Notes_inputs():
     input_map = dict(add=dict(argstr='-a "%s"',
     ),
     add_history=dict(argstr='-h "%s"',
-    xor=[u'rep_history'],
+    xor=['rep_history'],
     ),
     args=dict(argstr='%s',
     ),
@@ -27,7 +28,7 @@ def test_Notes_inputs():
     ),
     outputtype=dict(),
     rep_history=dict(argstr='-HH "%s"',
-    xor=[u'add_history'],
+    xor=['add_history'],
     ),
     ses=dict(argstr='-ses',
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_OutlierCount.py b/nipype/interfaces/afni/tests/test_auto_OutlierCount.py
--- a/nipype/interfaces/afni/tests/test_auto_OutlierCount.py
+++ b/nipype/interfaces/afni/tests/test_auto_OutlierCount.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import OutlierCount
 
 
@@ -7,11 +8,11 @@ def test_OutlierCount_inputs():
     ),
     autoclip=dict(argstr='-autoclip',
     usedefault=True,
-    xor=[u'in_file'],
+    xor=['in_file'],
     ),
     automask=dict(argstr='-automask',
     usedefault=True,
-    xor=[u'in_file'],
+    xor=['in_file'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -33,17 +34,17 @@ def test_OutlierCount_inputs():
     usedefault=True,
     ),
     mask=dict(argstr='-mask %s',
-    xor=[u'autoclip', u'automask'],
+    xor=['autoclip', 'automask'],
     ),
     out_file=dict(argstr='> %s',
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_outliers',
     position=-1,
     ),
     outliers_file=dict(argstr='-save %s',
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_outliers',
     output_name='out_outliers',
     ),
@@ -66,7 +67,7 @@ def test_OutlierCount_inputs():
 def test_OutlierCount_outputs():
     output_map = dict(out_file=dict(argstr='> %s',
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tqual',
     position=-1,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_QualityIndex.py b/nipype/interfaces/afni/tests/test_auto_QualityIndex.py
--- a/nipype/interfaces/afni/tests/test_auto_QualityIndex.py
+++ b/nipype/interfaces/afni/tests/test_auto_QualityIndex.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import QualityIndex
 
 
@@ -7,11 +8,11 @@ def test_QualityIndex_inputs():
     ),
     autoclip=dict(argstr='-autoclip',
     usedefault=True,
-    xor=[u'mask'],
+    xor=['mask'],
     ),
     automask=dict(argstr='-automask',
     usedefault=True,
-    xor=[u'mask'],
+    xor=['mask'],
     ),
     clip=dict(argstr='-clip %f',
     ),
@@ -29,11 +30,11 @@ def test_QualityIndex_inputs():
     usedefault=True,
     ),
     mask=dict(argstr='-mask %s',
-    xor=[u'autoclip', u'automask'],
+    xor=['autoclip', 'automask'],
     ),
     out_file=dict(argstr='> %s',
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tqual',
     position=-1,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_ROIStats.py b/nipype/interfaces/afni/tests/test_auto_ROIStats.py
--- a/nipype/interfaces/afni/tests/test_auto_ROIStats.py
+++ b/nipype/interfaces/afni/tests/test_auto_ROIStats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ROIStats
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Refit.py b/nipype/interfaces/afni/tests/test_auto_Refit.py
--- a/nipype/interfaces/afni/tests/test_auto_Refit.py
+++ b/nipype/interfaces/afni/tests/test_auto_Refit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Refit
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Resample.py b/nipype/interfaces/afni/tests/test_auto_Resample.py
--- a/nipype/interfaces/afni/tests/test_auto_Resample.py
+++ b/nipype/interfaces/afni/tests/test_auto_Resample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Resample
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Retroicor.py b/nipype/interfaces/afni/tests/test_auto_Retroicor.py
--- a/nipype/interfaces/afni/tests/test_auto_Retroicor.py
+++ b/nipype/interfaces/afni/tests/test_auto_Retroicor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Retroicor
 
 
@@ -27,7 +28,7 @@ def test_Retroicor_inputs():
     position=-5,
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_retroicor',
     position=1,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_SVMTest.py b/nipype/interfaces/afni/tests/test_auto_SVMTest.py
--- a/nipype/interfaces/afni/tests/test_auto_SVMTest.py
+++ b/nipype/interfaces/afni/tests/test_auto_SVMTest.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..svm import SVMTest
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_SVMTrain.py b/nipype/interfaces/afni/tests/test_auto_SVMTrain.py
--- a/nipype/interfaces/afni/tests/test_auto_SVMTrain.py
+++ b/nipype/interfaces/afni/tests/test_auto_SVMTrain.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..svm import SVMTrain
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Seg.py b/nipype/interfaces/afni/tests/test_auto_Seg.py
--- a/nipype/interfaces/afni/tests/test_auto_Seg.py
+++ b/nipype/interfaces/afni/tests/test_auto_Seg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Seg
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_SkullStrip.py b/nipype/interfaces/afni/tests/test_auto_SkullStrip.py
--- a/nipype/interfaces/afni/tests/test_auto_SkullStrip.py
+++ b/nipype/interfaces/afni/tests/test_auto_SkullStrip.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SkullStrip
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_TCat.py b/nipype/interfaces/afni/tests/test_auto_TCat.py
--- a/nipype/interfaces/afni/tests/test_auto_TCat.py
+++ b/nipype/interfaces/afni/tests/test_auto_TCat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TCat
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_TCorr1D.py b/nipype/interfaces/afni/tests/test_auto_TCorr1D.py
--- a/nipype/interfaces/afni/tests/test_auto_TCorr1D.py
+++ b/nipype/interfaces/afni/tests/test_auto_TCorr1D.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import TCorr1D
 
 
@@ -13,7 +14,7 @@ def test_TCorr1D_inputs():
     ),
     ktaub=dict(argstr=' -ktaub',
     position=1,
-    xor=[u'pearson', u'spearman', u'quadrant'],
+    xor=['pearson', 'spearman', 'quadrant'],
     ),
     out_file=dict(argstr='-prefix %s',
     keep_extension=True,
@@ -23,15 +24,15 @@ def test_TCorr1D_inputs():
     outputtype=dict(),
     pearson=dict(argstr=' -pearson',
     position=1,
-    xor=[u'spearman', u'quadrant', u'ktaub'],
+    xor=['spearman', 'quadrant', 'ktaub'],
     ),
     quadrant=dict(argstr=' -quadrant',
     position=1,
-    xor=[u'pearson', u'spearman', u'ktaub'],
+    xor=['pearson', 'spearman', 'ktaub'],
     ),
     spearman=dict(argstr=' -spearman',
     position=1,
-    xor=[u'pearson', u'quadrant', u'ktaub'],
+    xor=['pearson', 'quadrant', 'ktaub'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/afni/tests/test_auto_TCorrMap.py b/nipype/interfaces/afni/tests/test_auto_TCorrMap.py
--- a/nipype/interfaces/afni/tests/test_auto_TCorrMap.py
+++ b/nipype/interfaces/afni/tests/test_auto_TCorrMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import TCorrMap
 
 
@@ -6,7 +7,7 @@ def test_TCorrMap_inputs():
     input_map = dict(absolute_threshold=dict(argstr='-Thresh %f %s',
     name_source='in_file',
     suffix='_thresh',
-    xor=(u'absolute_threshold', u'var_absolute_threshold', u'var_absolute_threshold_normalize'),
+    xor=('absolute_threshold', 'var_absolute_threshold', 'var_absolute_threshold_normalize'),
     ),
     args=dict(argstr='%s',
     ),
@@ -15,12 +16,12 @@ def test_TCorrMap_inputs():
     average_expr=dict(argstr='-Aexpr %s %s',
     name_source='in_file',
     suffix='_aexpr',
-    xor=(u'average_expr', u'average_expr_nonzero', u'sum_expr'),
+    xor=('average_expr', 'average_expr_nonzero', 'sum_expr'),
     ),
     average_expr_nonzero=dict(argstr='-Cexpr %s %s',
     name_source='in_file',
     suffix='_cexpr',
-    xor=(u'average_expr', u'average_expr_nonzero', u'sum_expr'),
+    xor=('average_expr', 'average_expr_nonzero', 'sum_expr'),
     ),
     bandpass=dict(argstr='-bpass %f %f',
     ),
@@ -55,7 +56,7 @@ def test_TCorrMap_inputs():
     suffix='_mean',
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_afni',
     ),
     outputtype=dict(),
@@ -80,7 +81,7 @@ def test_TCorrMap_inputs():
     sum_expr=dict(argstr='-Sexpr %s %s',
     name_source='in_file',
     suffix='_sexpr',
-    xor=(u'average_expr', u'average_expr_nonzero', u'sum_expr'),
+    xor=('average_expr', 'average_expr_nonzero', 'sum_expr'),
     ),
     terminal_output=dict(nohash=True,
     ),
@@ -88,12 +89,12 @@ def test_TCorrMap_inputs():
     var_absolute_threshold=dict(argstr='-VarThresh %f %f %f %s',
     name_source='in_file',
     suffix='_varthresh',
-    xor=(u'absolute_threshold', u'var_absolute_threshold', u'var_absolute_threshold_normalize'),
+    xor=('absolute_threshold', 'var_absolute_threshold', 'var_absolute_threshold_normalize'),
     ),
     var_absolute_threshold_normalize=dict(argstr='-VarThreshN %f %f %f %s',
     name_source='in_file',
     suffix='_varthreshn',
-    xor=(u'absolute_threshold', u'var_absolute_threshold', u'var_absolute_threshold_normalize'),
+    xor=('absolute_threshold', 'var_absolute_threshold', 'var_absolute_threshold_normalize'),
     ),
     zmean=dict(argstr='-Zmean %s',
     name_source='in_file',
diff --git a/nipype/interfaces/afni/tests/test_auto_TCorrelate.py b/nipype/interfaces/afni/tests/test_auto_TCorrelate.py
--- a/nipype/interfaces/afni/tests/test_auto_TCorrelate.py
+++ b/nipype/interfaces/afni/tests/test_auto_TCorrelate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import TCorrelate
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_TShift.py b/nipype/interfaces/afni/tests/test_auto_TShift.py
--- a/nipype/interfaces/afni/tests/test_auto_TShift.py
+++ b/nipype/interfaces/afni/tests/test_auto_TShift.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import TShift
 
 
@@ -36,10 +37,10 @@ def test_TShift_inputs():
     tr=dict(argstr='-TR %s',
     ),
     tslice=dict(argstr='-slice %s',
-    xor=[u'tzero'],
+    xor=['tzero'],
     ),
     tzero=dict(argstr='-tzero %s',
-    xor=[u'tslice'],
+    xor=['tslice'],
     ),
     )
     inputs = TShift.input_spec()
diff --git a/nipype/interfaces/afni/tests/test_auto_TStat.py b/nipype/interfaces/afni/tests/test_auto_TStat.py
--- a/nipype/interfaces/afni/tests/test_auto_TStat.py
+++ b/nipype/interfaces/afni/tests/test_auto_TStat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TStat
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_To3D.py b/nipype/interfaces/afni/tests/test_auto_To3D.py
--- a/nipype/interfaces/afni/tests/test_auto_To3D.py
+++ b/nipype/interfaces/afni/tests/test_auto_To3D.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import To3D
 
 
@@ -24,7 +25,7 @@ def test_To3D_inputs():
     position=-1,
     ),
     out_file=dict(argstr='-prefix %s',
-    name_source=[u'in_folder'],
+    name_source=['in_folder'],
     name_template='%s',
     ),
     outputtype=dict(),
diff --git a/nipype/interfaces/afni/tests/test_auto_Volreg.py b/nipype/interfaces/afni/tests/test_auto_Volreg.py
--- a/nipype/interfaces/afni/tests/test_auto_Volreg.py
+++ b/nipype/interfaces/afni/tests/test_auto_Volreg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Volreg
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_Warp.py b/nipype/interfaces/afni/tests/test_auto_Warp.py
--- a/nipype/interfaces/afni/tests/test_auto_Warp.py
+++ b/nipype/interfaces/afni/tests/test_auto_Warp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Warp
 
 
diff --git a/nipype/interfaces/afni/tests/test_auto_ZCutUp.py b/nipype/interfaces/afni/tests/test_auto_ZCutUp.py
--- a/nipype/interfaces/afni/tests/test_auto_ZCutUp.py
+++ b/nipype/interfaces/afni/tests/test_auto_ZCutUp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ZCutUp
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_ANTS.py b/nipype/interfaces/ants/tests/test_auto_ANTS.py
--- a/nipype/interfaces/ants/tests/test_auto_ANTS.py
+++ b/nipype/interfaces/ants/tests/test_auto_ANTS.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import ANTS
 
 
@@ -7,7 +8,7 @@ def test_ANTS_inputs():
     ),
     args=dict(argstr='%s',
     ),
-    delta_time=dict(requires=[u'number_of_time_steps'],
+    delta_time=dict(requires=['number_of_time_steps'],
     ),
     dimension=dict(argstr='%d',
     position=1,
@@ -18,14 +19,14 @@ def test_ANTS_inputs():
     ),
     fixed_image=dict(mandatory=True,
     ),
-    gradient_step_length=dict(requires=[u'transformation_model'],
+    gradient_step_length=dict(requires=['transformation_model'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
     ),
     metric=dict(mandatory=True,
     ),
-    metric_weight=dict(requires=[u'metric'],
+    metric_weight=dict(requires=['metric'],
     ),
     mi_option=dict(argstr='--MI-option %s',
     sep='x',
@@ -42,19 +43,19 @@ def test_ANTS_inputs():
     number_of_iterations=dict(argstr='--number-of-iterations %s',
     sep='x',
     ),
-    number_of_time_steps=dict(requires=[u'gradient_step_length'],
+    number_of_time_steps=dict(requires=['gradient_step_length'],
     ),
     output_transform_prefix=dict(argstr='--output-naming %s',
     mandatory=True,
     usedefault=True,
     ),
-    radius=dict(requires=[u'metric'],
+    radius=dict(requires=['metric'],
     ),
     regularization=dict(argstr='%s',
     ),
-    regularization_deformation_field_sigma=dict(requires=[u'regularization'],
+    regularization_deformation_field_sigma=dict(requires=['regularization'],
     ),
-    regularization_gradient_field_sigma=dict(requires=[u'regularization'],
+    regularization_gradient_field_sigma=dict(requires=['regularization'],
     ),
     smoothing_sigmas=dict(argstr='--gaussian-smoothing-sigmas %s',
     sep='x',
@@ -62,7 +63,7 @@ def test_ANTS_inputs():
     subsampling_factors=dict(argstr='--subsampling-factors %s',
     sep='x',
     ),
-    symmetry_type=dict(requires=[u'delta_time'],
+    symmetry_type=dict(requires=['delta_time'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/ants/tests/test_auto_ANTSCommand.py b/nipype/interfaces/ants/tests/test_auto_ANTSCommand.py
--- a/nipype/interfaces/ants/tests/test_auto_ANTSCommand.py
+++ b/nipype/interfaces/ants/tests/test_auto_ANTSCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import ANTSCommand
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_AntsJointFusion.py b/nipype/interfaces/ants/tests/test_auto_AntsJointFusion.py
--- a/nipype/interfaces/ants/tests/test_auto_AntsJointFusion.py
+++ b/nipype/interfaces/ants/tests/test_auto_AntsJointFusion.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import AntsJointFusion
 
 
@@ -28,7 +29,7 @@ def test_AntsJointFusion_inputs():
     ),
     exclusion_image=dict(),
     exclusion_image_label=dict(argstr='-e %s',
-    requires=[u'exclusion_image'],
+    requires=['exclusion_image'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -38,14 +39,14 @@ def test_AntsJointFusion_inputs():
     num_threads=dict(nohash=True,
     usedefault=True,
     ),
-    out_atlas_voting_weight_name_format=dict(requires=[u'out_label_fusion', u'out_intensity_fusion_name_format', u'out_label_post_prob_name_format'],
+    out_atlas_voting_weight_name_format=dict(requires=['out_label_fusion', 'out_intensity_fusion_name_format', 'out_label_post_prob_name_format'],
     ),
     out_intensity_fusion_name_format=dict(argstr='',
     ),
     out_label_fusion=dict(argstr='%s',
     hash_files=False,
     ),
-    out_label_post_prob_name_format=dict(requires=[u'out_label_fusion', u'out_intensity_fusion_name_format'],
+    out_label_post_prob_name_format=dict(requires=['out_label_fusion', 'out_intensity_fusion_name_format'],
     ),
     patch_metric=dict(argstr='-m %s',
     usedefault=False,
@@ -58,7 +59,7 @@ def test_AntsJointFusion_inputs():
     usedefault=True,
     ),
     retain_label_posterior_images=dict(argstr='-r',
-    requires=[u'atlas_segmentation_image'],
+    requires=['atlas_segmentation_image'],
     usedefault=True,
     ),
     search_radius=dict(argstr='-s %s',
diff --git a/nipype/interfaces/ants/tests/test_auto_ApplyTransforms.py b/nipype/interfaces/ants/tests/test_auto_ApplyTransforms.py
--- a/nipype/interfaces/ants/tests/test_auto_ApplyTransforms.py
+++ b/nipype/interfaces/ants/tests/test_auto_ApplyTransforms.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..resampling import ApplyTransforms
 
 
@@ -37,7 +38,7 @@ def test_ApplyTransforms_inputs():
     genfile=True,
     hash_files=False,
     ),
-    print_out_composite_warp_file=dict(requires=[u'output_image'],
+    print_out_composite_warp_file=dict(requires=['output_image'],
     ),
     reference_image=dict(argstr='--reference-image %s',
     mandatory=True,
diff --git a/nipype/interfaces/ants/tests/test_auto_ApplyTransformsToPoints.py b/nipype/interfaces/ants/tests/test_auto_ApplyTransformsToPoints.py
--- a/nipype/interfaces/ants/tests/test_auto_ApplyTransformsToPoints.py
+++ b/nipype/interfaces/ants/tests/test_auto_ApplyTransformsToPoints.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..resampling import ApplyTransformsToPoints
 
 
@@ -22,7 +23,7 @@ def test_ApplyTransformsToPoints_inputs():
     ),
     output_file=dict(argstr='--output %s',
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_transformed.csv',
     ),
     terminal_output=dict(nohash=True,
diff --git a/nipype/interfaces/ants/tests/test_auto_Atropos.py b/nipype/interfaces/ants/tests/test_auto_Atropos.py
--- a/nipype/interfaces/ants/tests/test_auto_Atropos.py
+++ b/nipype/interfaces/ants/tests/test_auto_Atropos.py
@@ -1,11 +1,12 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import Atropos
 
 
 def test_Atropos_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
-    convergence_threshold=dict(requires=[u'n_iterations'],
+    convergence_threshold=dict(requires=['n_iterations'],
     ),
     dimension=dict(argstr='--image-dimensionality %d',
     usedefault=True,
@@ -20,7 +21,7 @@ def test_Atropos_inputs():
     ),
     initialization=dict(argstr='%s',
     mandatory=True,
-    requires=[u'number_of_tissue_classes'],
+    requires=['number_of_tissue_classes'],
     ),
     intensity_images=dict(argstr='--intensity-image %s...',
     mandatory=True,
@@ -30,9 +31,9 @@ def test_Atropos_inputs():
     mask_image=dict(argstr='--mask-image %s',
     mandatory=True,
     ),
-    maximum_number_of_icm_terations=dict(requires=[u'icm_use_synchronous_update'],
+    maximum_number_of_icm_terations=dict(requires=['icm_use_synchronous_update'],
     ),
-    mrf_radius=dict(requires=[u'mrf_smoothing_factor'],
+    mrf_radius=dict(requires=['mrf_smoothing_factor'],
     ),
     mrf_smoothing_factor=dict(argstr='%s',
     ),
@@ -52,13 +53,13 @@ def test_Atropos_inputs():
     posterior_formulation=dict(argstr='%s',
     ),
     prior_probability_images=dict(),
-    prior_probability_threshold=dict(requires=[u'prior_weighting'],
+    prior_probability_threshold=dict(requires=['prior_weighting'],
     ),
     prior_weighting=dict(),
     save_posteriors=dict(),
     terminal_output=dict(nohash=True,
     ),
-    use_mixture_model_proportions=dict(requires=[u'posterior_formulation'],
+    use_mixture_model_proportions=dict(requires=['posterior_formulation'],
     ),
     use_random_seed=dict(argstr='--use-random-seed %d',
     usedefault=True,
diff --git a/nipype/interfaces/ants/tests/test_auto_AverageAffineTransform.py b/nipype/interfaces/ants/tests/test_auto_AverageAffineTransform.py
--- a/nipype/interfaces/ants/tests/test_auto_AverageAffineTransform.py
+++ b/nipype/interfaces/ants/tests/test_auto_AverageAffineTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import AverageAffineTransform
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_AverageImages.py b/nipype/interfaces/ants/tests/test_auto_AverageImages.py
--- a/nipype/interfaces/ants/tests/test_auto_AverageImages.py
+++ b/nipype/interfaces/ants/tests/test_auto_AverageImages.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import AverageImages
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_BrainExtraction.py b/nipype/interfaces/ants/tests/test_auto_BrainExtraction.py
--- a/nipype/interfaces/ants/tests/test_auto_BrainExtraction.py
+++ b/nipype/interfaces/ants/tests/test_auto_BrainExtraction.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import BrainExtraction
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_ConvertScalarImageToRGB.py b/nipype/interfaces/ants/tests/test_auto_ConvertScalarImageToRGB.py
--- a/nipype/interfaces/ants/tests/test_auto_ConvertScalarImageToRGB.py
+++ b/nipype/interfaces/ants/tests/test_auto_ConvertScalarImageToRGB.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..visualization import ConvertScalarImageToRGB
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_CorticalThickness.py b/nipype/interfaces/ants/tests/test_auto_CorticalThickness.py
--- a/nipype/interfaces/ants/tests/test_auto_CorticalThickness.py
+++ b/nipype/interfaces/ants/tests/test_auto_CorticalThickness.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import CorticalThickness
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_CreateJacobianDeterminantImage.py b/nipype/interfaces/ants/tests/test_auto_CreateJacobianDeterminantImage.py
--- a/nipype/interfaces/ants/tests/test_auto_CreateJacobianDeterminantImage.py
+++ b/nipype/interfaces/ants/tests/test_auto_CreateJacobianDeterminantImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import CreateJacobianDeterminantImage
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_CreateTiledMosaic.py b/nipype/interfaces/ants/tests/test_auto_CreateTiledMosaic.py
--- a/nipype/interfaces/ants/tests/test_auto_CreateTiledMosaic.py
+++ b/nipype/interfaces/ants/tests/test_auto_CreateTiledMosaic.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..visualization import CreateTiledMosaic
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_DenoiseImage.py b/nipype/interfaces/ants/tests/test_auto_DenoiseImage.py
--- a/nipype/interfaces/ants/tests/test_auto_DenoiseImage.py
+++ b/nipype/interfaces/ants/tests/test_auto_DenoiseImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import DenoiseImage
 
 
@@ -19,7 +20,7 @@ def test_DenoiseImage_inputs():
     ),
     noise_image=dict(hash_files=False,
     keep_extension=True,
-    name_source=[u'input_image'],
+    name_source=['input_image'],
     name_template='%s_noise',
     ),
     noise_model=dict(argstr='-n %s',
@@ -31,12 +32,12 @@ def test_DenoiseImage_inputs():
     output_image=dict(argstr='-o %s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'input_image'],
+    name_source=['input_image'],
     name_template='%s_noise_corrected',
     ),
     save_noise=dict(mandatory=True,
     usedefault=True,
-    xor=[u'noise_image'],
+    xor=['noise_image'],
     ),
     shrink_factor=dict(argstr='-s %s',
     usedefault=True,
diff --git a/nipype/interfaces/ants/tests/test_auto_GenWarpFields.py b/nipype/interfaces/ants/tests/test_auto_GenWarpFields.py
--- a/nipype/interfaces/ants/tests/test_auto_GenWarpFields.py
+++ b/nipype/interfaces/ants/tests/test_auto_GenWarpFields.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..legacy import GenWarpFields
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_JointFusion.py b/nipype/interfaces/ants/tests/test_auto_JointFusion.py
--- a/nipype/interfaces/ants/tests/test_auto_JointFusion.py
+++ b/nipype/interfaces/ants/tests/test_auto_JointFusion.py
@@ -1,9 +1,10 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import JointFusion
 
 
 def test_JointFusion_inputs():
-    input_map = dict(alpha=dict(requires=[u'method'],
+    input_map = dict(alpha=dict(requires=['method'],
     usedefault=True,
     ),
     args=dict(argstr='%s',
@@ -12,7 +13,7 @@ def test_JointFusion_inputs():
     ),
     atlas_group_weights=dict(argstr='-gpw %d...',
     ),
-    beta=dict(requires=[u'method'],
+    beta=dict(requires=['method'],
     usedefault=True,
     ),
     dimension=dict(argstr='%d',
diff --git a/nipype/interfaces/ants/tests/test_auto_LaplacianThickness.py b/nipype/interfaces/ants/tests/test_auto_LaplacianThickness.py
--- a/nipype/interfaces/ants/tests/test_auto_LaplacianThickness.py
+++ b/nipype/interfaces/ants/tests/test_auto_LaplacianThickness.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import LaplacianThickness
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_MultiplyImages.py b/nipype/interfaces/ants/tests/test_auto_MultiplyImages.py
--- a/nipype/interfaces/ants/tests/test_auto_MultiplyImages.py
+++ b/nipype/interfaces/ants/tests/test_auto_MultiplyImages.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MultiplyImages
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_N4BiasFieldCorrection.py b/nipype/interfaces/ants/tests/test_auto_N4BiasFieldCorrection.py
--- a/nipype/interfaces/ants/tests/test_auto_N4BiasFieldCorrection.py
+++ b/nipype/interfaces/ants/tests/test_auto_N4BiasFieldCorrection.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import N4BiasFieldCorrection
 
 
@@ -9,9 +10,9 @@ def test_N4BiasFieldCorrection_inputs():
     ),
     bspline_fitting_distance=dict(argstr='--bspline-fitting %s',
     ),
-    bspline_order=dict(requires=[u'bspline_fitting_distance'],
+    bspline_order=dict(requires=['bspline_fitting_distance'],
     ),
-    convergence_threshold=dict(requires=[u'n_iterations'],
+    convergence_threshold=dict(requires=['n_iterations'],
     ),
     dimension=dict(argstr='-d %d',
     usedefault=True,
@@ -38,7 +39,7 @@ def test_N4BiasFieldCorrection_inputs():
     ),
     save_bias=dict(mandatory=True,
     usedefault=True,
-    xor=[u'bias_image'],
+    xor=['bias_image'],
     ),
     shrink_factor=dict(argstr='--shrink-factor %d',
     ),
diff --git a/nipype/interfaces/ants/tests/test_auto_Registration.py b/nipype/interfaces/ants/tests/test_auto_Registration.py
--- a/nipype/interfaces/ants/tests/test_auto_Registration.py
+++ b/nipype/interfaces/ants/tests/test_auto_Registration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import Registration
 
 
@@ -8,10 +9,10 @@ def test_Registration_inputs():
     collapse_output_transforms=dict(argstr='--collapse-output-transforms %d',
     usedefault=True,
     ),
-    convergence_threshold=dict(requires=[u'number_of_iterations'],
+    convergence_threshold=dict(requires=['number_of_iterations'],
     usedefault=True,
     ),
-    convergence_window_size=dict(requires=[u'convergence_threshold'],
+    convergence_window_size=dict(requires=['convergence_threshold'],
     usedefault=True,
     ),
     dimension=dict(argstr='--dimensionality %d',
@@ -30,10 +31,10 @@ def test_Registration_inputs():
     usedefault=True,
     ),
     initial_moving_transform=dict(argstr='%s',
-    xor=[u'initial_moving_transform_com'],
+    xor=['initial_moving_transform_com'],
     ),
     initial_moving_transform_com=dict(argstr='%s',
-    xor=[u'initial_moving_transform'],
+    xor=['initial_moving_transform'],
     ),
     initialize_transforms_per_stage=dict(argstr='--initialize-transforms-per-stage %d',
     usedefault=True,
@@ -42,29 +43,29 @@ def test_Registration_inputs():
     usedefault=True,
     ),
     interpolation_parameters=dict(),
-    invert_initial_moving_transform=dict(requires=[u'initial_moving_transform'],
-    xor=[u'initial_moving_transform_com'],
+    invert_initial_moving_transform=dict(requires=['initial_moving_transform'],
+    xor=['initial_moving_transform_com'],
     ),
     metric=dict(mandatory=True,
     ),
     metric_item_trait=dict(),
     metric_stage_trait=dict(),
     metric_weight=dict(mandatory=True,
-    requires=[u'metric'],
+    requires=['metric'],
     usedefault=True,
     ),
     metric_weight_item_trait=dict(),
     metric_weight_stage_trait=dict(),
     moving_image=dict(mandatory=True,
     ),
-    moving_image_mask=dict(requires=[u'fixed_image_mask'],
+    moving_image_mask=dict(requires=['fixed_image_mask'],
     ),
     num_threads=dict(nohash=True,
     usedefault=True,
     ),
     number_of_iterations=dict(),
     output_inverse_warped_image=dict(hash_files=False,
-    requires=[u'output_warped_image'],
+    requires=['output_warped_image'],
     ),
     output_transform_prefix=dict(argstr='%s',
     usedefault=True,
@@ -73,16 +74,16 @@ def test_Registration_inputs():
     ),
     radius_bins_item_trait=dict(),
     radius_bins_stage_trait=dict(),
-    radius_or_number_of_bins=dict(requires=[u'metric_weight'],
+    radius_or_number_of_bins=dict(requires=['metric_weight'],
     usedefault=True,
     ),
     restore_state=dict(argstr='--restore-state %s',
     ),
-    sampling_percentage=dict(requires=[u'sampling_strategy'],
+    sampling_percentage=dict(requires=['sampling_strategy'],
     ),
     sampling_percentage_item_trait=dict(),
     sampling_percentage_stage_trait=dict(),
-    sampling_strategy=dict(requires=[u'metric_weight'],
+    sampling_strategy=dict(requires=['metric_weight'],
     ),
     sampling_strategy_item_trait=dict(),
     sampling_strategy_stage_trait=dict(),
@@ -90,7 +91,7 @@ def test_Registration_inputs():
     ),
     shrink_factors=dict(mandatory=True,
     ),
-    sigma_units=dict(requires=[u'smoothing_sigmas'],
+    sigma_units=dict(requires=['smoothing_sigmas'],
     ),
     smoothing_sigmas=dict(mandatory=True,
     ),
diff --git a/nipype/interfaces/ants/tests/test_auto_WarpImageMultiTransform.py b/nipype/interfaces/ants/tests/test_auto_WarpImageMultiTransform.py
--- a/nipype/interfaces/ants/tests/test_auto_WarpImageMultiTransform.py
+++ b/nipype/interfaces/ants/tests/test_auto_WarpImageMultiTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..resampling import WarpImageMultiTransform
 
 
@@ -25,23 +26,23 @@ def test_WarpImageMultiTransform_inputs():
     ),
     out_postfix=dict(hash_files=False,
     usedefault=True,
-    xor=[u'output_image'],
+    xor=['output_image'],
     ),
     output_image=dict(argstr='%s',
     genfile=True,
     hash_files=False,
     position=3,
-    xor=[u'out_postfix'],
+    xor=['out_postfix'],
     ),
     reference_image=dict(argstr='-R %s',
-    xor=[u'tightest_box'],
+    xor=['tightest_box'],
     ),
     reslice_by_header=dict(argstr='--reslice-by-header',
     ),
     terminal_output=dict(nohash=True,
     ),
     tightest_box=dict(argstr='--tightest-bounding-box',
-    xor=[u'reference_image'],
+    xor=['reference_image'],
     ),
     transformation_series=dict(argstr='%s',
     mandatory=True,
diff --git a/nipype/interfaces/ants/tests/test_auto_WarpTimeSeriesImageMultiTransform.py b/nipype/interfaces/ants/tests/test_auto_WarpTimeSeriesImageMultiTransform.py
--- a/nipype/interfaces/ants/tests/test_auto_WarpTimeSeriesImageMultiTransform.py
+++ b/nipype/interfaces/ants/tests/test_auto_WarpTimeSeriesImageMultiTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..resampling import WarpTimeSeriesImageMultiTransform
 
 
@@ -27,14 +28,14 @@ def test_WarpTimeSeriesImageMultiTransform_inputs():
     usedefault=True,
     ),
     reference_image=dict(argstr='-R %s',
-    xor=[u'tightest_box'],
+    xor=['tightest_box'],
     ),
     reslice_by_header=dict(argstr='--reslice-by-header',
     ),
     terminal_output=dict(nohash=True,
     ),
     tightest_box=dict(argstr='--tightest-bounding-box',
-    xor=[u'reference_image'],
+    xor=['reference_image'],
     ),
     transformation_series=dict(argstr='%s',
     copyfile=False,
diff --git a/nipype/interfaces/ants/tests/test_auto_antsBrainExtraction.py b/nipype/interfaces/ants/tests/test_auto_antsBrainExtraction.py
--- a/nipype/interfaces/ants/tests/test_auto_antsBrainExtraction.py
+++ b/nipype/interfaces/ants/tests/test_auto_antsBrainExtraction.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import antsBrainExtraction
 
 
@@ -55,7 +56,23 @@ def test_antsBrainExtraction_inputs():
 
 def test_antsBrainExtraction_outputs():
     output_map = dict(BrainExtractionBrain=dict(),
+    BrainExtractionCSF=dict(),
+    BrainExtractionGM=dict(),
+    BrainExtractionInitialAffine=dict(),
+    BrainExtractionInitialAffineFixed=dict(),
+    BrainExtractionInitialAffineMoving=dict(),
+    BrainExtractionLaplacian=dict(),
     BrainExtractionMask=dict(),
+    BrainExtractionPrior0GenericAffine=dict(),
+    BrainExtractionPrior1InverseWarp=dict(),
+    BrainExtractionPrior1Warp=dict(),
+    BrainExtractionPriorWarped=dict(),
+    BrainExtractionSegmentation=dict(),
+    BrainExtractionTemplateLaplacian=dict(),
+    BrainExtractionTmp=dict(),
+    BrainExtractionWM=dict(),
+    N4Corrected0=dict(),
+    N4Truncated0=dict(),
     )
     outputs = antsBrainExtraction.output_spec()
 
diff --git a/nipype/interfaces/ants/tests/test_auto_antsCorticalThickness.py b/nipype/interfaces/ants/tests/test_auto_antsCorticalThickness.py
--- a/nipype/interfaces/ants/tests/test_auto_antsCorticalThickness.py
+++ b/nipype/interfaces/ants/tests/test_auto_antsCorticalThickness.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import antsCorticalThickness
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_antsIntroduction.py b/nipype/interfaces/ants/tests/test_auto_antsIntroduction.py
--- a/nipype/interfaces/ants/tests/test_auto_antsIntroduction.py
+++ b/nipype/interfaces/ants/tests/test_auto_antsIntroduction.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..legacy import antsIntroduction
 
 
diff --git a/nipype/interfaces/ants/tests/test_auto_buildtemplateparallel.py b/nipype/interfaces/ants/tests/test_auto_buildtemplateparallel.py
--- a/nipype/interfaces/ants/tests/test_auto_buildtemplateparallel.py
+++ b/nipype/interfaces/ants/tests/test_auto_buildtemplateparallel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..legacy import buildtemplateparallel
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_BDP.py b/nipype/interfaces/brainsuite/tests/test_auto_BDP.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_BDP.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_BDP.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import BDP
 
 
@@ -6,21 +7,21 @@ def test_BDP_inputs():
     input_map = dict(BVecBValPair=dict(argstr='--bvec %s --bval %s',
     mandatory=True,
     position=-1,
-    xor=[u'bMatrixFile'],
+    xor=['bMatrixFile'],
     ),
     args=dict(argstr='%s',
     ),
     bMatrixFile=dict(argstr='--bmat %s',
     mandatory=True,
     position=-1,
-    xor=[u'BVecBValPair'],
+    xor=['BVecBValPair'],
     ),
     bValRatioThreshold=dict(argstr='--bval-ratio-threshold %f',
     ),
     bfcFile=dict(argstr='%s',
     mandatory=True,
     position=0,
-    xor=[u'noStructuralRegistration'],
+    xor=['noStructuralRegistration'],
     ),
     customDiffusionLabel=dict(argstr='--custom-diffusion-label %s',
     ),
@@ -50,10 +51,10 @@ def test_BDP_inputs():
     estimateTensors=dict(argstr='--tensors',
     ),
     fieldmapCorrection=dict(argstr='--fieldmap-correction %s',
-    requires=[u'echoSpacing'],
+    requires=['echoSpacing'],
     ),
     fieldmapCorrectionMethod=dict(argstr='--fieldmap-correction-method %s',
-    xor=[u'skipIntensityCorr'],
+    xor=['skipIntensityCorr'],
     ),
     fieldmapSmooth=dict(argstr='--fieldmap-smooth3=%f',
     ),
@@ -79,7 +80,7 @@ def test_BDP_inputs():
     noStructuralRegistration=dict(argstr='--no-structural-registration',
     mandatory=True,
     position=0,
-    xor=[u'bfcFile'],
+    xor=['bfcFile'],
     ),
     odfLambta=dict(argstr='--odf-lambda <L>',
     ),
@@ -98,7 +99,7 @@ def test_BDP_inputs():
     skipDistortionCorr=dict(argstr='--no-distortion-correction',
     ),
     skipIntensityCorr=dict(argstr='--no-intensity-correction',
-    xor=[u'fieldmapCorrectionMethod'],
+    xor=['fieldmapCorrectionMethod'],
     ),
     skipNonuniformityCorr=dict(argstr='--no-nonuniformity-correction',
     ),
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Bfc.py b/nipype/interfaces/brainsuite/tests/test_auto_Bfc.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Bfc.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Bfc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Bfc
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Bse.py b/nipype/interfaces/brainsuite/tests/test_auto_Bse.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Bse.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Bse.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Bse
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Cerebro.py b/nipype/interfaces/brainsuite/tests/test_auto_Cerebro.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Cerebro.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Cerebro.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Cerebro
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Cortex.py b/nipype/interfaces/brainsuite/tests/test_auto_Cortex.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Cortex.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Cortex.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Cortex
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Dewisp.py b/nipype/interfaces/brainsuite/tests/test_auto_Dewisp.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Dewisp.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Dewisp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Dewisp
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Dfs.py b/nipype/interfaces/brainsuite/tests/test_auto_Dfs.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Dfs.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Dfs.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Dfs
 
 
@@ -22,7 +23,7 @@ def test_Dfs_inputs():
     noNormalsFlag=dict(argstr='--nonormals',
     ),
     nonZeroTessellation=dict(argstr='-nz',
-    xor=(u'nonZeroTessellation', u'specialTessellation'),
+    xor=('nonZeroTessellation', 'specialTessellation'),
     ),
     outputSurfaceFile=dict(argstr='-o %s',
     genfile=True,
@@ -39,8 +40,8 @@ def test_Dfs_inputs():
     ),
     specialTessellation=dict(argstr='%s',
     position=-1,
-    requires=[u'tessellationThreshold'],
-    xor=(u'nonZeroTessellation', u'specialTessellation'),
+    requires=['tessellationThreshold'],
+    xor=('nonZeroTessellation', 'specialTessellation'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Hemisplit.py b/nipype/interfaces/brainsuite/tests/test_auto_Hemisplit.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Hemisplit.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Hemisplit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Hemisplit
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Pialmesh.py b/nipype/interfaces/brainsuite/tests/test_auto_Pialmesh.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Pialmesh.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Pialmesh.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Pialmesh
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Pvc.py b/nipype/interfaces/brainsuite/tests/test_auto_Pvc.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Pvc.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Pvc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Pvc
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_SVReg.py b/nipype/interfaces/brainsuite/tests/test_auto_SVReg.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_SVReg.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_SVReg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import SVReg
 
 
@@ -53,13 +54,13 @@ def test_SVReg_inputs():
     useSingleThreading=dict(argstr="'-U'",
     ),
     verbosity0=dict(argstr="'-v0'",
-    xor=(u'verbosity0', u'verbosity1', u'verbosity2'),
+    xor=('verbosity0', 'verbosity1', 'verbosity2'),
     ),
     verbosity1=dict(argstr="'-v1'",
-    xor=(u'verbosity0', u'verbosity1', u'verbosity2'),
+    xor=('verbosity0', 'verbosity1', 'verbosity2'),
     ),
     verbosity2=dict(argstr="'v2'",
-    xor=(u'verbosity0', u'verbosity1', u'verbosity2'),
+    xor=('verbosity0', 'verbosity1', 'verbosity2'),
     ),
     )
     inputs = SVReg.input_spec()
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Scrubmask.py b/nipype/interfaces/brainsuite/tests/test_auto_Scrubmask.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Scrubmask.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Scrubmask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Scrubmask
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Skullfinder.py b/nipype/interfaces/brainsuite/tests/test_auto_Skullfinder.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Skullfinder.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Skullfinder.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Skullfinder
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_Tca.py b/nipype/interfaces/brainsuite/tests/test_auto_Tca.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_Tca.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_Tca.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import Tca
 
 
diff --git a/nipype/interfaces/brainsuite/tests/test_auto_ThicknessPVC.py b/nipype/interfaces/brainsuite/tests/test_auto_ThicknessPVC.py
--- a/nipype/interfaces/brainsuite/tests/test_auto_ThicknessPVC.py
+++ b/nipype/interfaces/brainsuite/tests/test_auto_ThicknessPVC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsuite import ThicknessPVC
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_AnalyzeHeader.py b/nipype/interfaces/camino/tests/test_auto_AnalyzeHeader.py
--- a/nipype/interfaces/camino/tests/test_auto_AnalyzeHeader.py
+++ b/nipype/interfaces/camino/tests/test_auto_AnalyzeHeader.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import AnalyzeHeader
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ComputeEigensystem.py b/nipype/interfaces/camino/tests/test_auto_ComputeEigensystem.py
--- a/nipype/interfaces/camino/tests/test_auto_ComputeEigensystem.py
+++ b/nipype/interfaces/camino/tests/test_auto_ComputeEigensystem.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ComputeEigensystem
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ComputeFractionalAnisotropy.py b/nipype/interfaces/camino/tests/test_auto_ComputeFractionalAnisotropy.py
--- a/nipype/interfaces/camino/tests/test_auto_ComputeFractionalAnisotropy.py
+++ b/nipype/interfaces/camino/tests/test_auto_ComputeFractionalAnisotropy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ComputeFractionalAnisotropy
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ComputeMeanDiffusivity.py b/nipype/interfaces/camino/tests/test_auto_ComputeMeanDiffusivity.py
--- a/nipype/interfaces/camino/tests/test_auto_ComputeMeanDiffusivity.py
+++ b/nipype/interfaces/camino/tests/test_auto_ComputeMeanDiffusivity.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ComputeMeanDiffusivity
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ComputeTensorTrace.py b/nipype/interfaces/camino/tests/test_auto_ComputeTensorTrace.py
--- a/nipype/interfaces/camino/tests/test_auto_ComputeTensorTrace.py
+++ b/nipype/interfaces/camino/tests/test_auto_ComputeTensorTrace.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ComputeTensorTrace
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_Conmat.py b/nipype/interfaces/camino/tests/test_auto_Conmat.py
--- a/nipype/interfaces/camino/tests/test_auto_Conmat.py
+++ b/nipype/interfaces/camino/tests/test_auto_Conmat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..connectivity import Conmat
 
 
@@ -18,7 +19,7 @@ def test_Conmat_inputs():
     genfile=True,
     ),
     scalar_file=dict(argstr='-scalarfile %s',
-    requires=[u'tract_stat'],
+    requires=['tract_stat'],
     ),
     target_file=dict(argstr='-targetfile %s',
     mandatory=True,
@@ -29,12 +30,12 @@ def test_Conmat_inputs():
     ),
     tract_prop=dict(argstr='-tractstat %s',
     units='NA',
-    xor=[u'tract_stat'],
+    xor=['tract_stat'],
     ),
     tract_stat=dict(argstr='-tractstat %s',
-    requires=[u'scalar_file'],
+    requires=['scalar_file'],
     units='NA',
-    xor=[u'tract_prop'],
+    xor=['tract_prop'],
     ),
     )
     inputs = Conmat.input_spec()
diff --git a/nipype/interfaces/camino/tests/test_auto_DT2NIfTI.py b/nipype/interfaces/camino/tests/test_auto_DT2NIfTI.py
--- a/nipype/interfaces/camino/tests/test_auto_DT2NIfTI.py
+++ b/nipype/interfaces/camino/tests/test_auto_DT2NIfTI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import DT2NIfTI
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_DTIFit.py b/nipype/interfaces/camino/tests/test_auto_DTIFit.py
--- a/nipype/interfaces/camino/tests/test_auto_DTIFit.py
+++ b/nipype/interfaces/camino/tests/test_auto_DTIFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTIFit
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_DTLUTGen.py b/nipype/interfaces/camino/tests/test_auto_DTLUTGen.py
--- a/nipype/interfaces/camino/tests/test_auto_DTLUTGen.py
+++ b/nipype/interfaces/camino/tests/test_auto_DTLUTGen.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTLUTGen
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_DTMetric.py b/nipype/interfaces/camino/tests/test_auto_DTMetric.py
--- a/nipype/interfaces/camino/tests/test_auto_DTMetric.py
+++ b/nipype/interfaces/camino/tests/test_auto_DTMetric.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTMetric
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_FSL2Scheme.py b/nipype/interfaces/camino/tests/test_auto_FSL2Scheme.py
--- a/nipype/interfaces/camino/tests/test_auto_FSL2Scheme.py
+++ b/nipype/interfaces/camino/tests/test_auto_FSL2Scheme.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import FSL2Scheme
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_Image2Voxel.py b/nipype/interfaces/camino/tests/test_auto_Image2Voxel.py
--- a/nipype/interfaces/camino/tests/test_auto_Image2Voxel.py
+++ b/nipype/interfaces/camino/tests/test_auto_Image2Voxel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import Image2Voxel
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ImageStats.py b/nipype/interfaces/camino/tests/test_auto_ImageStats.py
--- a/nipype/interfaces/camino/tests/test_auto_ImageStats.py
+++ b/nipype/interfaces/camino/tests/test_auto_ImageStats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ImageStats
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_LinRecon.py b/nipype/interfaces/camino/tests/test_auto_LinRecon.py
--- a/nipype/interfaces/camino/tests/test_auto_LinRecon.py
+++ b/nipype/interfaces/camino/tests/test_auto_LinRecon.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import LinRecon
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_MESD.py b/nipype/interfaces/camino/tests/test_auto_MESD.py
--- a/nipype/interfaces/camino/tests/test_auto_MESD.py
+++ b/nipype/interfaces/camino/tests/test_auto_MESD.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import MESD
 
 
@@ -11,7 +12,7 @@ def test_MESD_inputs():
     usedefault=True,
     ),
     fastmesd=dict(argstr='-fastmesd',
-    requires=[u'mepointset'],
+    requires=['mepointset'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/camino/tests/test_auto_ModelFit.py b/nipype/interfaces/camino/tests/test_auto_ModelFit.py
--- a/nipype/interfaces/camino/tests/test_auto_ModelFit.py
+++ b/nipype/interfaces/camino/tests/test_auto_ModelFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ModelFit
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_NIfTIDT2Camino.py b/nipype/interfaces/camino/tests/test_auto_NIfTIDT2Camino.py
--- a/nipype/interfaces/camino/tests/test_auto_NIfTIDT2Camino.py
+++ b/nipype/interfaces/camino/tests/test_auto_NIfTIDT2Camino.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import NIfTIDT2Camino
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_PicoPDFs.py b/nipype/interfaces/camino/tests/test_auto_PicoPDFs.py
--- a/nipype/interfaces/camino/tests/test_auto_PicoPDFs.py
+++ b/nipype/interfaces/camino/tests/test_auto_PicoPDFs.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import PicoPDFs
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_ProcStreamlines.py b/nipype/interfaces/camino/tests/test_auto_ProcStreamlines.py
--- a/nipype/interfaces/camino/tests/test_auto_ProcStreamlines.py
+++ b/nipype/interfaces/camino/tests/test_auto_ProcStreamlines.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import ProcStreamlines
 
 
@@ -56,18 +57,18 @@ def test_ProcStreamlines_inputs():
     position=-1,
     ),
     outputacm=dict(argstr='-outputacm',
-    requires=[u'outputroot', u'seedfile'],
+    requires=['outputroot', 'seedfile'],
     ),
     outputcbs=dict(argstr='-outputcbs',
-    requires=[u'outputroot', u'targetfile', u'seedfile'],
+    requires=['outputroot', 'targetfile', 'seedfile'],
     ),
     outputcp=dict(argstr='-outputcp',
-    requires=[u'outputroot', u'seedfile'],
+    requires=['outputroot', 'seedfile'],
     ),
     outputroot=dict(argstr='-outputroot %s',
     ),
     outputsc=dict(argstr='-outputsc',
-    requires=[u'outputroot', u'seedfile'],
+    requires=['outputroot', 'seedfile'],
     ),
     outputtracts=dict(argstr='-outputtracts',
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_QBallMX.py b/nipype/interfaces/camino/tests/test_auto_QBallMX.py
--- a/nipype/interfaces/camino/tests/test_auto_QBallMX.py
+++ b/nipype/interfaces/camino/tests/test_auto_QBallMX.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import QBallMX
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_SFLUTGen.py b/nipype/interfaces/camino/tests/test_auto_SFLUTGen.py
--- a/nipype/interfaces/camino/tests/test_auto_SFLUTGen.py
+++ b/nipype/interfaces/camino/tests/test_auto_SFLUTGen.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..calib import SFLUTGen
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_SFPICOCalibData.py b/nipype/interfaces/camino/tests/test_auto_SFPICOCalibData.py
--- a/nipype/interfaces/camino/tests/test_auto_SFPICOCalibData.py
+++ b/nipype/interfaces/camino/tests/test_auto_SFPICOCalibData.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..calib import SFPICOCalibData
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_SFPeaks.py b/nipype/interfaces/camino/tests/test_auto_SFPeaks.py
--- a/nipype/interfaces/camino/tests/test_auto_SFPeaks.py
+++ b/nipype/interfaces/camino/tests/test_auto_SFPeaks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import SFPeaks
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_Shredder.py b/nipype/interfaces/camino/tests/test_auto_Shredder.py
--- a/nipype/interfaces/camino/tests/test_auto_Shredder.py
+++ b/nipype/interfaces/camino/tests/test_auto_Shredder.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import Shredder
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_Track.py b/nipype/interfaces/camino/tests/test_auto_Track.py
--- a/nipype/interfaces/camino/tests/test_auto_Track.py
+++ b/nipype/interfaces/camino/tests/test_auto_Track.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import Track
 
 
@@ -10,7 +11,7 @@ def test_Track_inputs():
     args=dict(argstr='%s',
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -56,7 +57,7 @@ def test_Track_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackBallStick.py b/nipype/interfaces/camino/tests/test_auto_TrackBallStick.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackBallStick.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackBallStick.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackBallStick
 
 
@@ -10,7 +11,7 @@ def test_TrackBallStick_inputs():
     args=dict(argstr='%s',
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -56,7 +57,7 @@ def test_TrackBallStick_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackBayesDirac.py b/nipype/interfaces/camino/tests/test_auto_TrackBayesDirac.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackBayesDirac.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackBayesDirac.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackBayesDirac
 
 
@@ -10,7 +11,7 @@ def test_TrackBayesDirac_inputs():
     args=dict(argstr='%s',
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvepriorg=dict(argstr='-curvepriorg %G',
     ),
@@ -76,7 +77,7 @@ def test_TrackBayesDirac_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackBedpostxDeter.py b/nipype/interfaces/camino/tests/test_auto_TrackBedpostxDeter.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackBedpostxDeter.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackBedpostxDeter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackBedpostxDeter
 
 
@@ -13,7 +14,7 @@ def test_TrackBedpostxDeter_inputs():
     mandatory=True,
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -62,7 +63,7 @@ def test_TrackBedpostxDeter_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackBedpostxProba.py b/nipype/interfaces/camino/tests/test_auto_TrackBedpostxProba.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackBedpostxProba.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackBedpostxProba.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackBedpostxProba
 
 
@@ -13,7 +14,7 @@ def test_TrackBedpostxProba_inputs():
     mandatory=True,
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -65,7 +66,7 @@ def test_TrackBedpostxProba_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackBootstrap.py b/nipype/interfaces/camino/tests/test_auto_TrackBootstrap.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackBootstrap.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackBootstrap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackBootstrap
 
 
@@ -15,7 +16,7 @@ def test_TrackBootstrap_inputs():
     mandatory=True,
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -69,7 +70,7 @@ def test_TrackBootstrap_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackDT.py b/nipype/interfaces/camino/tests/test_auto_TrackDT.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackDT.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackDT.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackDT
 
 
@@ -10,7 +11,7 @@ def test_TrackDT_inputs():
     args=dict(argstr='%s',
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -56,7 +57,7 @@ def test_TrackDT_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TrackPICo.py b/nipype/interfaces/camino/tests/test_auto_TrackPICo.py
--- a/nipype/interfaces/camino/tests/test_auto_TrackPICo.py
+++ b/nipype/interfaces/camino/tests/test_auto_TrackPICo.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TrackPICo
 
 
@@ -10,7 +11,7 @@ def test_TrackPICo_inputs():
     args=dict(argstr='%s',
     ),
     curveinterval=dict(argstr='-curveinterval %f',
-    requires=[u'curvethresh'],
+    requires=['curvethresh'],
     ),
     curvethresh=dict(argstr='-curvethresh %f',
     ),
@@ -61,7 +62,7 @@ def test_TrackPICo_inputs():
     position=2,
     ),
     stepsize=dict(argstr='-stepsize %f',
-    requires=[u'tracker'],
+    requires=['tracker'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/camino/tests/test_auto_TractShredder.py b/nipype/interfaces/camino/tests/test_auto_TractShredder.py
--- a/nipype/interfaces/camino/tests/test_auto_TractShredder.py
+++ b/nipype/interfaces/camino/tests/test_auto_TractShredder.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import TractShredder
 
 
diff --git a/nipype/interfaces/camino/tests/test_auto_VtkStreamlines.py b/nipype/interfaces/camino/tests/test_auto_VtkStreamlines.py
--- a/nipype/interfaces/camino/tests/test_auto_VtkStreamlines.py
+++ b/nipype/interfaces/camino/tests/test_auto_VtkStreamlines.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import VtkStreamlines
 
 
diff --git a/nipype/interfaces/camino2trackvis/tests/test_auto_Camino2Trackvis.py b/nipype/interfaces/camino2trackvis/tests/test_auto_Camino2Trackvis.py
--- a/nipype/interfaces/camino2trackvis/tests/test_auto_Camino2Trackvis.py
+++ b/nipype/interfaces/camino2trackvis/tests/test_auto_Camino2Trackvis.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import Camino2Trackvis
 
 
diff --git a/nipype/interfaces/camino2trackvis/tests/test_auto_Trackvis2Camino.py b/nipype/interfaces/camino2trackvis/tests/test_auto_Trackvis2Camino.py
--- a/nipype/interfaces/camino2trackvis/tests/test_auto_Trackvis2Camino.py
+++ b/nipype/interfaces/camino2trackvis/tests/test_auto_Trackvis2Camino.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import Trackvis2Camino
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_AverageNetworks.py b/nipype/interfaces/cmtk/tests/test_auto_AverageNetworks.py
--- a/nipype/interfaces/cmtk/tests/test_auto_AverageNetworks.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_AverageNetworks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..nx import AverageNetworks
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_CFFConverter.py b/nipype/interfaces/cmtk/tests/test_auto_CFFConverter.py
--- a/nipype/interfaces/cmtk/tests/test_auto_CFFConverter.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_CFFConverter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import CFFConverter
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_CreateMatrix.py b/nipype/interfaces/cmtk/tests/test_auto_CreateMatrix.py
--- a/nipype/interfaces/cmtk/tests/test_auto_CreateMatrix.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_CreateMatrix.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..cmtk import CreateMatrix
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_CreateNodes.py b/nipype/interfaces/cmtk/tests/test_auto_CreateNodes.py
--- a/nipype/interfaces/cmtk/tests/test_auto_CreateNodes.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_CreateNodes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..cmtk import CreateNodes
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_MergeCNetworks.py b/nipype/interfaces/cmtk/tests/test_auto_MergeCNetworks.py
--- a/nipype/interfaces/cmtk/tests/test_auto_MergeCNetworks.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_MergeCNetworks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import MergeCNetworks
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_NetworkBasedStatistic.py b/nipype/interfaces/cmtk/tests/test_auto_NetworkBasedStatistic.py
--- a/nipype/interfaces/cmtk/tests/test_auto_NetworkBasedStatistic.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_NetworkBasedStatistic.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..nbs import NetworkBasedStatistic
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_NetworkXMetrics.py b/nipype/interfaces/cmtk/tests/test_auto_NetworkXMetrics.py
--- a/nipype/interfaces/cmtk/tests/test_auto_NetworkXMetrics.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_NetworkXMetrics.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..nx import NetworkXMetrics
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_Parcellate.py b/nipype/interfaces/cmtk/tests/test_auto_Parcellate.py
--- a/nipype/interfaces/cmtk/tests/test_auto_Parcellate.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_Parcellate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..parcellation import Parcellate
 
 
diff --git a/nipype/interfaces/cmtk/tests/test_auto_ROIGen.py b/nipype/interfaces/cmtk/tests/test_auto_ROIGen.py
--- a/nipype/interfaces/cmtk/tests/test_auto_ROIGen.py
+++ b/nipype/interfaces/cmtk/tests/test_auto_ROIGen.py
@@ -1,13 +1,14 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..cmtk import ROIGen
 
 
 def test_ROIGen_inputs():
-    input_map = dict(LUT_file=dict(xor=[u'use_freesurfer_LUT'],
+    input_map = dict(LUT_file=dict(xor=['use_freesurfer_LUT'],
     ),
     aparc_aseg_file=dict(mandatory=True,
     ),
-    freesurfer_dir=dict(requires=[u'use_freesurfer_LUT'],
+    freesurfer_dir=dict(requires=['use_freesurfer_LUT'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -16,7 +17,7 @@ def test_ROIGen_inputs():
     ),
     out_roi_file=dict(genfile=True,
     ),
-    use_freesurfer_LUT=dict(xor=[u'LUT_file'],
+    use_freesurfer_LUT=dict(xor=['LUT_file'],
     ),
     )
     inputs = ROIGen.input_spec()
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTIRecon.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTIRecon.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTIRecon.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTIRecon.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTIRecon
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTITracker.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTITracker.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTITracker.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_DTITracker.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTITracker
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_HARDIMat.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_HARDIMat.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_HARDIMat.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_HARDIMat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import HARDIMat
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFRecon.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFRecon.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFRecon.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFRecon.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import ODFRecon
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFTracker.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFTracker.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFTracker.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_ODFTracker.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..odf import ODFTracker
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_SplineFilter.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_SplineFilter.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_SplineFilter.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_SplineFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..postproc import SplineFilter
 
 
diff --git a/nipype/interfaces/diffusion_toolkit/tests/test_auto_TrackMerge.py b/nipype/interfaces/diffusion_toolkit/tests/test_auto_TrackMerge.py
--- a/nipype/interfaces/diffusion_toolkit/tests/test_auto_TrackMerge.py
+++ b/nipype/interfaces/diffusion_toolkit/tests/test_auto_TrackMerge.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..postproc import TrackMerge
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_CSD.py b/nipype/interfaces/dipy/tests/test_auto_CSD.py
--- a/nipype/interfaces/dipy/tests/test_auto_CSD.py
+++ b/nipype/interfaces/dipy/tests/test_auto_CSD.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..reconstruction import CSD
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_DTI.py b/nipype/interfaces/dipy/tests/test_auto_DTI.py
--- a/nipype/interfaces/dipy/tests/test_auto_DTI.py
+++ b/nipype/interfaces/dipy/tests/test_auto_DTI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import DTI
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_Denoise.py b/nipype/interfaces/dipy/tests/test_auto_Denoise.py
--- a/nipype/interfaces/dipy/tests/test_auto_Denoise.py
+++ b/nipype/interfaces/dipy/tests/test_auto_Denoise.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Denoise
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_DipyBaseInterface.py b/nipype/interfaces/dipy/tests/test_auto_DipyBaseInterface.py
--- a/nipype/interfaces/dipy/tests/test_auto_DipyBaseInterface.py
+++ b/nipype/interfaces/dipy/tests/test_auto_DipyBaseInterface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import DipyBaseInterface
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_DipyDiffusionInterface.py b/nipype/interfaces/dipy/tests/test_auto_DipyDiffusionInterface.py
--- a/nipype/interfaces/dipy/tests/test_auto_DipyDiffusionInterface.py
+++ b/nipype/interfaces/dipy/tests/test_auto_DipyDiffusionInterface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import DipyDiffusionInterface
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_EstimateResponseSH.py b/nipype/interfaces/dipy/tests/test_auto_EstimateResponseSH.py
--- a/nipype/interfaces/dipy/tests/test_auto_EstimateResponseSH.py
+++ b/nipype/interfaces/dipy/tests/test_auto_EstimateResponseSH.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..reconstruction import EstimateResponseSH
 
 
 def test_EstimateResponseSH_inputs():
     input_map = dict(auto=dict(usedefault=True,
-    xor=[u'recursive'],
+    xor=['recursive'],
     ),
     b0_thres=dict(usedefault=True,
     ),
@@ -26,7 +27,7 @@ def test_EstimateResponseSH_inputs():
     ),
     out_prefix=dict(),
     recursive=dict(usedefault=True,
-    xor=[u'auto'],
+    xor=['auto'],
     ),
     response=dict(usedefault=True,
     ),
diff --git a/nipype/interfaces/dipy/tests/test_auto_RESTORE.py b/nipype/interfaces/dipy/tests/test_auto_RESTORE.py
--- a/nipype/interfaces/dipy/tests/test_auto_RESTORE.py
+++ b/nipype/interfaces/dipy/tests/test_auto_RESTORE.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..reconstruction import RESTORE
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_Resample.py b/nipype/interfaces/dipy/tests/test_auto_Resample.py
--- a/nipype/interfaces/dipy/tests/test_auto_Resample.py
+++ b/nipype/interfaces/dipy/tests/test_auto_Resample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Resample
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_SimulateMultiTensor.py b/nipype/interfaces/dipy/tests/test_auto_SimulateMultiTensor.py
--- a/nipype/interfaces/dipy/tests/test_auto_SimulateMultiTensor.py
+++ b/nipype/interfaces/dipy/tests/test_auto_SimulateMultiTensor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..simulate import SimulateMultiTensor
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_StreamlineTractography.py b/nipype/interfaces/dipy/tests/test_auto_StreamlineTractography.py
--- a/nipype/interfaces/dipy/tests/test_auto_StreamlineTractography.py
+++ b/nipype/interfaces/dipy/tests/test_auto_StreamlineTractography.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracks import StreamlineTractography
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_TensorMode.py b/nipype/interfaces/dipy/tests/test_auto_TensorMode.py
--- a/nipype/interfaces/dipy/tests/test_auto_TensorMode.py
+++ b/nipype/interfaces/dipy/tests/test_auto_TensorMode.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import TensorMode
 
 
diff --git a/nipype/interfaces/dipy/tests/test_auto_TrackDensityMap.py b/nipype/interfaces/dipy/tests/test_auto_TrackDensityMap.py
--- a/nipype/interfaces/dipy/tests/test_auto_TrackDensityMap.py
+++ b/nipype/interfaces/dipy/tests/test_auto_TrackDensityMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracks import TrackDensityMap
 
 
diff --git a/nipype/interfaces/elastix/tests/test_auto_AnalyzeWarp.py b/nipype/interfaces/elastix/tests/test_auto_AnalyzeWarp.py
--- a/nipype/interfaces/elastix/tests/test_auto_AnalyzeWarp.py
+++ b/nipype/interfaces/elastix/tests/test_auto_AnalyzeWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import AnalyzeWarp
 
 
diff --git a/nipype/interfaces/elastix/tests/test_auto_ApplyWarp.py b/nipype/interfaces/elastix/tests/test_auto_ApplyWarp.py
--- a/nipype/interfaces/elastix/tests/test_auto_ApplyWarp.py
+++ b/nipype/interfaces/elastix/tests/test_auto_ApplyWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import ApplyWarp
 
 
diff --git a/nipype/interfaces/elastix/tests/test_auto_EditTransform.py b/nipype/interfaces/elastix/tests/test_auto_EditTransform.py
--- a/nipype/interfaces/elastix/tests/test_auto_EditTransform.py
+++ b/nipype/interfaces/elastix/tests/test_auto_EditTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import EditTransform
 
 
diff --git a/nipype/interfaces/elastix/tests/test_auto_PointsWarp.py b/nipype/interfaces/elastix/tests/test_auto_PointsWarp.py
--- a/nipype/interfaces/elastix/tests/test_auto_PointsWarp.py
+++ b/nipype/interfaces/elastix/tests/test_auto_PointsWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import PointsWarp
 
 
diff --git a/nipype/interfaces/elastix/tests/test_auto_Registration.py b/nipype/interfaces/elastix/tests/test_auto_Registration.py
--- a/nipype/interfaces/elastix/tests/test_auto_Registration.py
+++ b/nipype/interfaces/elastix/tests/test_auto_Registration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import Registration
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_AddXFormToHeader.py b/nipype/interfaces/freesurfer/tests/test_auto_AddXFormToHeader.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_AddXFormToHeader.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_AddXFormToHeader.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import AddXFormToHeader
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Aparc2Aseg.py b/nipype/interfaces/freesurfer/tests/test_auto_Aparc2Aseg.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Aparc2Aseg.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Aparc2Aseg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Aparc2Aseg
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Apas2Aseg.py b/nipype/interfaces/freesurfer/tests/test_auto_Apas2Aseg.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Apas2Aseg.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Apas2Aseg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Apas2Aseg
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ApplyMask.py b/nipype/interfaces/freesurfer/tests/test_auto_ApplyMask.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ApplyMask.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ApplyMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ApplyMask
 
 
@@ -28,7 +29,7 @@ def test_ApplyMask_inputs():
     out_file=dict(argstr='%s',
     hash_files=True,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_masked',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ApplyVolTransform.py b/nipype/interfaces/freesurfer/tests/test_auto_ApplyVolTransform.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ApplyVolTransform.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ApplyVolTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ApplyVolTransform
 
 
@@ -10,12 +11,12 @@ def test_ApplyVolTransform_inputs():
     ),
     fs_target=dict(argstr='--fstarg',
     mandatory=True,
-    requires=[u'reg_file'],
-    xor=(u'target_file', u'tal', u'fs_target'),
+    requires=['reg_file'],
+    xor=('target_file', 'tal', 'fs_target'),
     ),
     fsl_reg_file=dict(argstr='--fsl %s',
     mandatory=True,
-    xor=(u'reg_file', u'fsl_reg_file', u'xfm_reg_file', u'reg_header', u'subject'),
+    xor=('reg_file', 'fsl_reg_file', 'xfm_reg_file', 'reg_header', 'subject'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -25,22 +26,22 @@ def test_ApplyVolTransform_inputs():
     inverse=dict(argstr='--inv',
     ),
     invert_morph=dict(argstr='--inv-morph',
-    requires=[u'm3z_file'],
+    requires=['m3z_file'],
     ),
     m3z_file=dict(argstr='--m3z %s',
     ),
     no_ded_m3z_path=dict(argstr='--noDefM3zPath',
-    requires=[u'm3z_file'],
+    requires=['m3z_file'],
     ),
     no_resample=dict(argstr='--no-resample',
     ),
     reg_file=dict(argstr='--reg %s',
     mandatory=True,
-    xor=(u'reg_file', u'fsl_reg_file', u'xfm_reg_file', u'reg_header', u'subject'),
+    xor=('reg_file', 'fsl_reg_file', 'xfm_reg_file', 'reg_header', 'subject'),
     ),
     reg_header=dict(argstr='--regheader',
     mandatory=True,
-    xor=(u'reg_file', u'fsl_reg_file', u'xfm_reg_file', u'reg_header', u'subject'),
+    xor=('reg_file', 'fsl_reg_file', 'xfm_reg_file', 'reg_header', 'subject'),
     ),
     source_file=dict(argstr='--mov %s',
     copyfile=False,
@@ -48,18 +49,18 @@ def test_ApplyVolTransform_inputs():
     ),
     subject=dict(argstr='--s %s',
     mandatory=True,
-    xor=(u'reg_file', u'fsl_reg_file', u'xfm_reg_file', u'reg_header', u'subject'),
+    xor=('reg_file', 'fsl_reg_file', 'xfm_reg_file', 'reg_header', 'subject'),
     ),
     subjects_dir=dict(),
     tal=dict(argstr='--tal',
     mandatory=True,
-    xor=(u'target_file', u'tal', u'fs_target'),
+    xor=('target_file', 'tal', 'fs_target'),
     ),
     tal_resolution=dict(argstr='--talres %.10f',
     ),
     target_file=dict(argstr='--targ %s',
     mandatory=True,
-    xor=(u'target_file', u'tal', u'fs_target'),
+    xor=('target_file', 'tal', 'fs_target'),
     ),
     terminal_output=dict(nohash=True,
     ),
@@ -68,7 +69,7 @@ def test_ApplyVolTransform_inputs():
     ),
     xfm_reg_file=dict(argstr='--xfm %s',
     mandatory=True,
-    xor=(u'reg_file', u'fsl_reg_file', u'xfm_reg_file', u'reg_header', u'subject'),
+    xor=('reg_file', 'fsl_reg_file', 'xfm_reg_file', 'reg_header', 'subject'),
     ),
     )
     inputs = ApplyVolTransform.input_spec()
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_BBRegister.py b/nipype/interfaces/freesurfer/tests/test_auto_BBRegister.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_BBRegister.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_BBRegister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import BBRegister
 
 
@@ -17,11 +18,11 @@ def test_BBRegister_inputs():
     usedefault=True,
     ),
     init=dict(argstr='--init-%s',
-    xor=[u'init_reg_file'],
+    xor=['init_reg_file'],
     ),
     init_reg_file=dict(argstr='--init-reg %s',
     mandatory=True,
-    xor=[u'init'],
+    xor=['init'],
     ),
     intermediate_file=dict(argstr='--int %s',
     ),
@@ -31,10 +32,10 @@ def test_BBRegister_inputs():
     genfile=True,
     ),
     reg_frame=dict(argstr='--frame %d',
-    xor=[u'reg_middle_frame'],
+    xor=['reg_middle_frame'],
     ),
     reg_middle_frame=dict(argstr='--mid-frame',
-    xor=[u'reg_frame'],
+    xor=['reg_frame'],
     ),
     registered_file=dict(argstr='--o %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Binarize.py b/nipype/interfaces/freesurfer/tests/test_auto_Binarize.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Binarize.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Binarize.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Binarize
 
 
@@ -45,12 +46,12 @@ def test_Binarize_inputs():
     match=dict(argstr='--match %d...',
     ),
     max=dict(argstr='--max %f',
-    xor=[u'wm_ven_csf'],
+    xor=['wm_ven_csf'],
     ),
     merge_file=dict(argstr='--merge %s',
     ),
     min=dict(argstr='--min %f',
-    xor=[u'wm_ven_csf'],
+    xor=['wm_ven_csf'],
     ),
     out_type=dict(argstr='',
     ),
@@ -66,7 +67,7 @@ def test_Binarize_inputs():
     wm=dict(argstr='--wm',
     ),
     wm_ven_csf=dict(argstr='--wm+vcsf',
-    xor=[u'min', u'max'],
+    xor=['min', 'max'],
     ),
     zero_edges=dict(argstr='--zero-edges',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_CALabel.py b/nipype/interfaces/freesurfer/tests/test_auto_CALabel.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_CALabel.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_CALabel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import CALabel
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_CANormalize.py b/nipype/interfaces/freesurfer/tests/test_auto_CANormalize.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_CANormalize.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_CANormalize.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import CANormalize
 
 
@@ -28,7 +29,7 @@ def test_CANormalize_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_norm',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_CARegister.py b/nipype/interfaces/freesurfer/tests/test_auto_CARegister.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_CARegister.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_CARegister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import CARegister
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_CheckTalairachAlignment.py b/nipype/interfaces/freesurfer/tests/test_auto_CheckTalairachAlignment.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_CheckTalairachAlignment.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_CheckTalairachAlignment.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import CheckTalairachAlignment
 
 
@@ -14,12 +15,12 @@ def test_CheckTalairachAlignment_inputs():
     in_file=dict(argstr='-xfm %s',
     mandatory=True,
     position=-1,
-    xor=[u'subject'],
+    xor=['subject'],
     ),
     subject=dict(argstr='-subj %s',
     mandatory=True,
     position=-1,
-    xor=[u'in_file'],
+    xor=['in_file'],
     ),
     subjects_dir=dict(),
     terminal_output=dict(nohash=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Concatenate.py b/nipype/interfaces/freesurfer/tests/test_auto_Concatenate.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Concatenate.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Concatenate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Concatenate
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ConcatenateLTA.py b/nipype/interfaces/freesurfer/tests/test_auto_ConcatenateLTA.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ConcatenateLTA.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ConcatenateLTA.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ConcatenateLTA
 
 
@@ -22,7 +23,7 @@ def test_ConcatenateLTA_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_lta1'],
+    name_source=['in_lta1'],
     name_template='%s-long',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Contrast.py b/nipype/interfaces/freesurfer/tests/test_auto_Contrast.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Contrast.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Contrast.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Contrast
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Curvature.py b/nipype/interfaces/freesurfer/tests/test_auto_Curvature.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Curvature.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Curvature.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Curvature
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_CurvatureStats.py b/nipype/interfaces/freesurfer/tests/test_auto_CurvatureStats.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_CurvatureStats.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_CurvatureStats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import CurvatureStats
 
 
@@ -28,7 +29,7 @@ def test_CurvatureStats_inputs():
     ),
     out_file=dict(argstr='-o %s',
     hash_files=False,
-    name_source=[u'hemisphere'],
+    name_source=['hemisphere'],
     name_template='%s.curv.stats',
     ),
     subject_id=dict(argstr='%s',
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_DICOMConvert.py b/nipype/interfaces/freesurfer/tests/test_auto_DICOMConvert.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_DICOMConvert.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_DICOMConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import DICOMConvert
 
 
@@ -17,11 +18,11 @@ def test_DICOMConvert_inputs():
     ignore_exception=dict(nohash=True,
     usedefault=True,
     ),
-    ignore_single_slice=dict(requires=[u'dicom_info'],
+    ignore_single_slice=dict(requires=['dicom_info'],
     ),
     out_type=dict(usedefault=True,
     ),
-    seq_list=dict(requires=[u'dicom_info'],
+    seq_list=dict(requires=['dicom_info'],
     ),
     subject_dir_template=dict(usedefault=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_EMRegister.py b/nipype/interfaces/freesurfer/tests/test_auto_EMRegister.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_EMRegister.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_EMRegister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import EMRegister
 
 
@@ -23,7 +24,7 @@ def test_EMRegister_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_transform.lta',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_EditWMwithAseg.py b/nipype/interfaces/freesurfer/tests/test_auto_EditWMwithAseg.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_EditWMwithAseg.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_EditWMwithAseg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import EditWMwithAseg
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_EulerNumber.py b/nipype/interfaces/freesurfer/tests/test_auto_EulerNumber.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_EulerNumber.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_EulerNumber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import EulerNumber
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ExtractMainComponent.py b/nipype/interfaces/freesurfer/tests/test_auto_ExtractMainComponent.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ExtractMainComponent.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ExtractMainComponent.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ExtractMainComponent
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FSCommand.py b/nipype/interfaces/freesurfer/tests/test_auto_FSCommand.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FSCommand.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FSCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import FSCommand
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FSCommandOpenMP.py b/nipype/interfaces/freesurfer/tests/test_auto_FSCommandOpenMP.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FSCommandOpenMP.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FSCommandOpenMP.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import FSCommandOpenMP
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FSScriptCommand.py b/nipype/interfaces/freesurfer/tests/test_auto_FSScriptCommand.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FSScriptCommand.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FSScriptCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import FSScriptCommand
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FitMSParams.py b/nipype/interfaces/freesurfer/tests/test_auto_FitMSParams.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FitMSParams.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FitMSParams.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FitMSParams
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FixTopology.py b/nipype/interfaces/freesurfer/tests/test_auto_FixTopology.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FixTopology.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FixTopology.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import FixTopology
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_FuseSegmentations.py b/nipype/interfaces/freesurfer/tests/test_auto_FuseSegmentations.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_FuseSegmentations.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_FuseSegmentations.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..longitudinal import FuseSegmentations
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_GLMFit.py b/nipype/interfaces/freesurfer/tests/test_auto_GLMFit.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_GLMFit.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_GLMFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import GLMFit
 
 
@@ -18,12 +19,12 @@ def test_GLMFit_inputs():
     contrast=dict(argstr='--C %s...',
     ),
     cortex=dict(argstr='--cortex',
-    xor=[u'label_file'],
+    xor=['label_file'],
     ),
     debug=dict(argstr='--debug',
     ),
     design=dict(argstr='--X %s',
-    xor=(u'fsgd', u'design', u'one_sample'),
+    xor=('fsgd', 'design', 'one_sample'),
     ),
     diag=dict(),
     diag_cluster=dict(argstr='--diag-cluster',
@@ -32,17 +33,17 @@ def test_GLMFit_inputs():
     usedefault=True,
     ),
     fixed_fx_dof=dict(argstr='--ffxdof %d',
-    xor=[u'fixed_fx_dof_file'],
+    xor=['fixed_fx_dof_file'],
     ),
     fixed_fx_dof_file=dict(argstr='--ffxdofdat %d',
-    xor=[u'fixed_fx_dof'],
+    xor=['fixed_fx_dof'],
     ),
     fixed_fx_var=dict(argstr='--yffxvar %s',
     ),
     force_perm=dict(argstr='--perm-force',
     ),
     fsgd=dict(argstr='--fsgd %s %s',
-    xor=(u'fsgd', u'design', u'one_sample'),
+    xor=('fsgd', 'design', 'one_sample'),
     ),
     fwhm=dict(argstr='--fwhm %f',
     ),
@@ -60,7 +61,7 @@ def test_GLMFit_inputs():
     invert_mask=dict(argstr='--mask-inv',
     ),
     label_file=dict(argstr='--label %s',
-    xor=[u'cortex'],
+    xor=['cortex'],
     ),
     mask_file=dict(argstr='--mask %s',
     ),
@@ -71,10 +72,10 @@ def test_GLMFit_inputs():
     no_mask_smooth=dict(argstr='--no-mask-smooth',
     ),
     no_prune=dict(argstr='--no-prune',
-    xor=[u'prunethresh'],
+    xor=['prunethresh'],
     ),
     one_sample=dict(argstr='--osgm',
-    xor=(u'one_sample', u'fsgd', u'design', u'contrast'),
+    xor=('one_sample', 'fsgd', 'design', 'contrast'),
     ),
     pca=dict(argstr='--pca',
     ),
@@ -85,7 +86,7 @@ def test_GLMFit_inputs():
     prune=dict(argstr='--prune',
     ),
     prune_thresh=dict(argstr='--prune_thr %f',
-    xor=[u'noprune'],
+    xor=['noprune'],
     ),
     resynth_test=dict(argstr='--resynthtest %d',
     ),
@@ -110,7 +111,7 @@ def test_GLMFit_inputs():
     subject_id=dict(),
     subjects_dir=dict(),
     surf=dict(argstr='--surf %s %s %s',
-    requires=[u'subject_id', u'hemi'],
+    requires=['subject_id', 'hemi'],
     ),
     surf_geo=dict(usedefault=True,
     ),
@@ -124,16 +125,16 @@ def test_GLMFit_inputs():
     ),
     vox_dump=dict(argstr='--voxdump %d %d %d',
     ),
-    weight_file=dict(xor=[u'weighted_ls'],
+    weight_file=dict(xor=['weighted_ls'],
     ),
     weight_inv=dict(argstr='--w-inv',
-    xor=[u'weighted_ls'],
+    xor=['weighted_ls'],
     ),
     weight_sqrt=dict(argstr='--w-sqrt',
-    xor=[u'weighted_ls'],
+    xor=['weighted_ls'],
     ),
     weighted_ls=dict(argstr='--wls %s',
-    xor=(u'weight_file', u'weight_inv', u'weight_sqrt'),
+    xor=('weight_file', 'weight_inv', 'weight_sqrt'),
     ),
     )
     inputs = GLMFit.input_spec()
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ImageInfo.py b/nipype/interfaces/freesurfer/tests/test_auto_ImageInfo.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ImageInfo.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ImageInfo.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ImageInfo
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Jacobian.py b/nipype/interfaces/freesurfer/tests/test_auto_Jacobian.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Jacobian.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Jacobian.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Jacobian
 
 
@@ -22,7 +23,7 @@ def test_Jacobian_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_origsurf'],
+    name_source=['in_origsurf'],
     name_template='%s.jacobian',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Label2Annot.py b/nipype/interfaces/freesurfer/tests/test_auto_Label2Annot.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Label2Annot.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Label2Annot.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Label2Annot
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Label2Label.py b/nipype/interfaces/freesurfer/tests/test_auto_Label2Label.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Label2Label.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Label2Label.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Label2Label
 
 
@@ -18,7 +19,7 @@ def test_Label2Label_inputs():
     out_file=dict(argstr='--trglabel %s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'source_label'],
+    name_source=['source_label'],
     name_template='%s_converted',
     ),
     registration_method=dict(argstr='--regmethod %s',
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Label2Vol.py b/nipype/interfaces/freesurfer/tests/test_auto_Label2Vol.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Label2Vol.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Label2Vol.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Label2Vol
 
 
@@ -6,12 +7,12 @@ def test_Label2Vol_inputs():
     input_map = dict(annot_file=dict(argstr='--annot %s',
     copyfile=False,
     mandatory=True,
-    requires=(u'subject_id', u'hemi'),
-    xor=(u'label_file', u'annot_file', u'seg_file', u'aparc_aseg'),
+    requires=('subject_id', 'hemi'),
+    xor=('label_file', 'annot_file', 'seg_file', 'aparc_aseg'),
     ),
     aparc_aseg=dict(argstr='--aparc+aseg',
     mandatory=True,
-    xor=(u'label_file', u'annot_file', u'seg_file', u'aparc_aseg'),
+    xor=('label_file', 'annot_file', 'seg_file', 'aparc_aseg'),
     ),
     args=dict(argstr='%s',
     ),
@@ -23,7 +24,7 @@ def test_Label2Vol_inputs():
     hemi=dict(argstr='--hemi %s',
     ),
     identity=dict(argstr='--identity',
-    xor=(u'reg_file', u'reg_header', u'identity'),
+    xor=('reg_file', 'reg_header', 'identity'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -33,7 +34,7 @@ def test_Label2Vol_inputs():
     label_file=dict(argstr='--label %s...',
     copyfile=False,
     mandatory=True,
-    xor=(u'label_file', u'annot_file', u'seg_file', u'aparc_aseg'),
+    xor=('label_file', 'annot_file', 'seg_file', 'aparc_aseg'),
     ),
     label_hit_file=dict(argstr='--hits %s',
     ),
@@ -44,18 +45,18 @@ def test_Label2Vol_inputs():
     native_vox2ras=dict(argstr='--native-vox2ras',
     ),
     proj=dict(argstr='--proj %s %f %f %f',
-    requires=(u'subject_id', u'hemi'),
+    requires=('subject_id', 'hemi'),
     ),
     reg_file=dict(argstr='--reg %s',
-    xor=(u'reg_file', u'reg_header', u'identity'),
+    xor=('reg_file', 'reg_header', 'identity'),
     ),
     reg_header=dict(argstr='--regheader %s',
-    xor=(u'reg_file', u'reg_header', u'identity'),
+    xor=('reg_file', 'reg_header', 'identity'),
     ),
     seg_file=dict(argstr='--seg %s',
     copyfile=False,
     mandatory=True,
-    xor=(u'label_file', u'annot_file', u'seg_file', u'aparc_aseg'),
+    xor=('label_file', 'annot_file', 'seg_file', 'aparc_aseg'),
     ),
     subject_id=dict(argstr='--subject %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MNIBiasCorrection.py b/nipype/interfaces/freesurfer/tests/test_auto_MNIBiasCorrection.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MNIBiasCorrection.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MNIBiasCorrection.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MNIBiasCorrection
 
 
@@ -25,7 +26,7 @@ def test_MNIBiasCorrection_inputs():
     out_file=dict(argstr='--o %s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_output',
     ),
     protocol_iterations=dict(argstr='--proto-iters %d',
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MPRtoMNI305.py b/nipype/interfaces/freesurfer/tests/test_auto_MPRtoMNI305.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MPRtoMNI305.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MPRtoMNI305.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import MPRtoMNI305
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIConvert.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIConvert.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIConvert.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRIConvert
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIFill.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIFill.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIFill.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIFill.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIFill
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIMarchingCubes.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIMarchingCubes.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIMarchingCubes.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIMarchingCubes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIMarchingCubes
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIPretess.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIPretess.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIPretess.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIPretess.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIPretess
 
 
@@ -30,7 +31,7 @@ def test_MRIPretess_inputs():
     ),
     out_file=dict(argstr='%s',
     keep_extension=True,
-    name_source=[u'in_filled'],
+    name_source=['in_filled'],
     name_template='%s_pretesswm',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRISPreproc.py b/nipype/interfaces/freesurfer/tests/test_auto_MRISPreproc.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRISPreproc.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRISPreproc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MRISPreproc
 
 
@@ -9,13 +10,13 @@ def test_MRISPreproc_inputs():
     usedefault=True,
     ),
     fsgd_file=dict(argstr='--fsgd %s',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     fwhm=dict(argstr='--fwhm %f',
-    xor=[u'num_iters'],
+    xor=['num_iters'],
     ),
     fwhm_source=dict(argstr='--fwhm-src %f',
-    xor=[u'num_iters_source'],
+    xor=['num_iters_source'],
     ),
     hemi=dict(argstr='--hemi %s',
     mandatory=True,
@@ -24,10 +25,10 @@ def test_MRISPreproc_inputs():
     usedefault=True,
     ),
     num_iters=dict(argstr='--niters %d',
-    xor=[u'fwhm'],
+    xor=['fwhm'],
     ),
     num_iters_source=dict(argstr='--niterssrc %d',
-    xor=[u'fwhm_source'],
+    xor=['fwhm_source'],
     ),
     out_file=dict(argstr='--out %s',
     genfile=True,
@@ -39,22 +40,22 @@ def test_MRISPreproc_inputs():
     source_format=dict(argstr='--srcfmt %s',
     ),
     subject_file=dict(argstr='--f %s',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     subjects=dict(argstr='--s %s...',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     subjects_dir=dict(),
     surf_area=dict(argstr='--area %s',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     surf_dir=dict(argstr='--surfdir %s',
     ),
     surf_measure=dict(argstr='--meas %s',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     surf_measure_file=dict(argstr='--is %s...',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     target=dict(argstr='--target %s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRISPreprocReconAll.py b/nipype/interfaces/freesurfer/tests/test_auto_MRISPreprocReconAll.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRISPreprocReconAll.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRISPreprocReconAll.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MRISPreprocReconAll
 
 
@@ -10,13 +11,13 @@ def test_MRISPreprocReconAll_inputs():
     usedefault=True,
     ),
     fsgd_file=dict(argstr='--fsgd %s',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     fwhm=dict(argstr='--fwhm %f',
-    xor=[u'num_iters'],
+    xor=['num_iters'],
     ),
     fwhm_source=dict(argstr='--fwhm-src %f',
-    xor=[u'num_iters_source'],
+    xor=['num_iters_source'],
     ),
     hemi=dict(argstr='--hemi %s',
     mandatory=True,
@@ -24,49 +25,49 @@ def test_MRISPreprocReconAll_inputs():
     ignore_exception=dict(nohash=True,
     usedefault=True,
     ),
-    lh_surfreg_target=dict(requires=[u'surfreg_files'],
+    lh_surfreg_target=dict(requires=['surfreg_files'],
     ),
     num_iters=dict(argstr='--niters %d',
-    xor=[u'fwhm'],
+    xor=['fwhm'],
     ),
     num_iters_source=dict(argstr='--niterssrc %d',
-    xor=[u'fwhm_source'],
+    xor=['fwhm_source'],
     ),
     out_file=dict(argstr='--out %s',
     genfile=True,
     ),
     proj_frac=dict(argstr='--projfrac %s',
     ),
-    rh_surfreg_target=dict(requires=[u'surfreg_files'],
+    rh_surfreg_target=dict(requires=['surfreg_files'],
     ),
     smooth_cortex_only=dict(argstr='--smooth-cortex-only',
     ),
     source_format=dict(argstr='--srcfmt %s',
     ),
     subject_file=dict(argstr='--f %s',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     subject_id=dict(argstr='--s %s',
     usedefault=True,
-    xor=(u'subjects', u'fsgd_file', u'subject_file', u'subject_id'),
+    xor=('subjects', 'fsgd_file', 'subject_file', 'subject_id'),
     ),
     subjects=dict(argstr='--s %s...',
-    xor=(u'subjects', u'fsgd_file', u'subject_file'),
+    xor=('subjects', 'fsgd_file', 'subject_file'),
     ),
     subjects_dir=dict(),
     surf_area=dict(argstr='--area %s',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     surf_dir=dict(argstr='--surfdir %s',
     ),
     surf_measure=dict(argstr='--meas %s',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     surf_measure_file=dict(argstr='--meas %s',
-    xor=(u'surf_measure', u'surf_measure_file', u'surf_area'),
+    xor=('surf_measure', 'surf_measure_file', 'surf_area'),
     ),
     surfreg_files=dict(argstr='--surfreg %s',
-    requires=[u'lh_surfreg_target', u'rh_surfreg_target'],
+    requires=['lh_surfreg_target', 'rh_surfreg_target'],
     ),
     target=dict(argstr='--target %s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRITessellate.py b/nipype/interfaces/freesurfer/tests/test_auto_MRITessellate.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRITessellate.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRITessellate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRITessellate
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIsCALabel.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIsCALabel.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIsCALabel.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIsCALabel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRIsCALabel
 
 
@@ -34,7 +35,7 @@ def test_MRIsCALabel_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'hemisphere'],
+    name_source=['hemisphere'],
     name_template='%s.aparc.annot',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIsCalc.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIsCalc.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIsCalc.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIsCalc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIsCalc
 
 
@@ -21,15 +22,15 @@ def test_MRIsCalc_inputs():
     ),
     in_file2=dict(argstr='%s',
     position=-1,
-    xor=[u'in_float', u'in_int'],
+    xor=['in_float', 'in_int'],
     ),
     in_float=dict(argstr='%f',
     position=-1,
-    xor=[u'in_file2', u'in_int'],
+    xor=['in_file2', 'in_int'],
     ),
     in_int=dict(argstr='%d',
     position=-1,
-    xor=[u'in_file2', u'in_float'],
+    xor=['in_file2', 'in_float'],
     ),
     out_file=dict(argstr='-o %s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIsConvert.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIsConvert.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIsConvert.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIsConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIsConvert
 
 
@@ -30,13 +31,13 @@ def test_MRIsConvert_inputs():
     origname=dict(argstr='-o %s',
     ),
     out_datatype=dict(mandatory=True,
-    xor=[u'out_file'],
+    xor=['out_file'],
     ),
     out_file=dict(argstr='%s',
     genfile=True,
     mandatory=True,
     position=-1,
-    xor=[u'out_datatype'],
+    xor=['out_datatype'],
     ),
     parcstats_file=dict(argstr='--parcstats %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MRIsInflate.py b/nipype/interfaces/freesurfer/tests/test_auto_MRIsInflate.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MRIsInflate.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MRIsInflate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MRIsInflate
 
 
@@ -17,16 +18,16 @@ def test_MRIsInflate_inputs():
     position=-2,
     ),
     no_save_sulc=dict(argstr='-no-save-sulc',
-    xor=[u'out_sulc'],
+    xor=['out_sulc'],
     ),
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s.inflated',
     position=-1,
     ),
-    out_sulc=dict(xor=[u'no_save_sulc'],
+    out_sulc=dict(xor=['no_save_sulc'],
     ),
     subjects_dir=dict(),
     terminal_output=dict(nohash=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MS_LDA.py b/nipype/interfaces/freesurfer/tests/test_auto_MS_LDA.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MS_LDA.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MS_LDA.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MS_LDA
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MakeAverageSubject.py b/nipype/interfaces/freesurfer/tests/test_auto_MakeAverageSubject.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MakeAverageSubject.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MakeAverageSubject.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MakeAverageSubject
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_MakeSurfaces.py b/nipype/interfaces/freesurfer/tests/test_auto_MakeSurfaces.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_MakeSurfaces.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_MakeSurfaces.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MakeSurfaces
 
 
@@ -24,7 +25,7 @@ def test_MakeSurfaces_inputs():
     ),
     in_filled=dict(mandatory=True,
     ),
-    in_label=dict(xor=[u'noaparc'],
+    in_label=dict(xor=['noaparc'],
     ),
     in_orig=dict(argstr='-orig %s',
     mandatory=True,
@@ -41,10 +42,10 @@ def test_MakeSurfaces_inputs():
     no_white=dict(argstr='-nowhite',
     ),
     noaparc=dict(argstr='-noaparc',
-    xor=[u'in_label'],
+    xor=['in_label'],
     ),
     orig_pial=dict(argstr='-orig_pial %s',
-    requires=[u'in_label'],
+    requires=['in_label'],
     ),
     orig_white=dict(argstr='-orig_white %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Normalize.py b/nipype/interfaces/freesurfer/tests/test_auto_Normalize.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Normalize.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Normalize.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Normalize
 
 
@@ -23,7 +24,7 @@ def test_Normalize_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_norm',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_OneSampleTTest.py b/nipype/interfaces/freesurfer/tests/test_auto_OneSampleTTest.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_OneSampleTTest.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_OneSampleTTest.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import OneSampleTTest
 
 
@@ -18,12 +19,12 @@ def test_OneSampleTTest_inputs():
     contrast=dict(argstr='--C %s...',
     ),
     cortex=dict(argstr='--cortex',
-    xor=[u'label_file'],
+    xor=['label_file'],
     ),
     debug=dict(argstr='--debug',
     ),
     design=dict(argstr='--X %s',
-    xor=(u'fsgd', u'design', u'one_sample'),
+    xor=('fsgd', 'design', 'one_sample'),
     ),
     diag=dict(),
     diag_cluster=dict(argstr='--diag-cluster',
@@ -32,17 +33,17 @@ def test_OneSampleTTest_inputs():
     usedefault=True,
     ),
     fixed_fx_dof=dict(argstr='--ffxdof %d',
-    xor=[u'fixed_fx_dof_file'],
+    xor=['fixed_fx_dof_file'],
     ),
     fixed_fx_dof_file=dict(argstr='--ffxdofdat %d',
-    xor=[u'fixed_fx_dof'],
+    xor=['fixed_fx_dof'],
     ),
     fixed_fx_var=dict(argstr='--yffxvar %s',
     ),
     force_perm=dict(argstr='--perm-force',
     ),
     fsgd=dict(argstr='--fsgd %s %s',
-    xor=(u'fsgd', u'design', u'one_sample'),
+    xor=('fsgd', 'design', 'one_sample'),
     ),
     fwhm=dict(argstr='--fwhm %f',
     ),
@@ -60,7 +61,7 @@ def test_OneSampleTTest_inputs():
     invert_mask=dict(argstr='--mask-inv',
     ),
     label_file=dict(argstr='--label %s',
-    xor=[u'cortex'],
+    xor=['cortex'],
     ),
     mask_file=dict(argstr='--mask %s',
     ),
@@ -71,10 +72,10 @@ def test_OneSampleTTest_inputs():
     no_mask_smooth=dict(argstr='--no-mask-smooth',
     ),
     no_prune=dict(argstr='--no-prune',
-    xor=[u'prunethresh'],
+    xor=['prunethresh'],
     ),
     one_sample=dict(argstr='--osgm',
-    xor=(u'one_sample', u'fsgd', u'design', u'contrast'),
+    xor=('one_sample', 'fsgd', 'design', 'contrast'),
     ),
     pca=dict(argstr='--pca',
     ),
@@ -85,7 +86,7 @@ def test_OneSampleTTest_inputs():
     prune=dict(argstr='--prune',
     ),
     prune_thresh=dict(argstr='--prune_thr %f',
-    xor=[u'noprune'],
+    xor=['noprune'],
     ),
     resynth_test=dict(argstr='--resynthtest %d',
     ),
@@ -110,7 +111,7 @@ def test_OneSampleTTest_inputs():
     subject_id=dict(),
     subjects_dir=dict(),
     surf=dict(argstr='--surf %s %s %s',
-    requires=[u'subject_id', u'hemi'],
+    requires=['subject_id', 'hemi'],
     ),
     surf_geo=dict(usedefault=True,
     ),
@@ -124,16 +125,16 @@ def test_OneSampleTTest_inputs():
     ),
     vox_dump=dict(argstr='--voxdump %d %d %d',
     ),
-    weight_file=dict(xor=[u'weighted_ls'],
+    weight_file=dict(xor=['weighted_ls'],
     ),
     weight_inv=dict(argstr='--w-inv',
-    xor=[u'weighted_ls'],
+    xor=['weighted_ls'],
     ),
     weight_sqrt=dict(argstr='--w-sqrt',
-    xor=[u'weighted_ls'],
+    xor=['weighted_ls'],
     ),
     weighted_ls=dict(argstr='--wls %s',
-    xor=(u'weight_file', u'weight_inv', u'weight_sqrt'),
+    xor=('weight_file', 'weight_inv', 'weight_sqrt'),
     ),
     )
     inputs = OneSampleTTest.input_spec()
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Paint.py b/nipype/interfaces/freesurfer/tests/test_auto_Paint.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Paint.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Paint.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import Paint
 
 
@@ -20,7 +21,7 @@ def test_Paint_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_surf'],
+    name_source=['in_surf'],
     name_template='%s.avg_curv',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ParcellationStats.py b/nipype/interfaces/freesurfer/tests/test_auto_ParcellationStats.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ParcellationStats.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ParcellationStats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ParcellationStats
 
 
@@ -22,12 +23,12 @@ def test_ParcellationStats_inputs():
     usedefault=True,
     ),
     in_annotation=dict(argstr='-a %s',
-    xor=[u'in_label'],
+    xor=['in_label'],
     ),
     in_cortex=dict(argstr='-cortex %s',
     ),
     in_label=dict(argstr='-l %s',
-    xor=[u'in_annotatoin', u'out_color'],
+    xor=['in_annotatoin', 'out_color'],
     ),
     lh_pial=dict(mandatory=True,
     ),
@@ -37,11 +38,11 @@ def test_ParcellationStats_inputs():
     ),
     out_color=dict(argstr='-c %s',
     genfile=True,
-    xor=[u'in_label'],
+    xor=['in_label'],
     ),
     out_table=dict(argstr='-f %s',
     genfile=True,
-    requires=[u'tabular_output'],
+    requires=['tabular_output'],
     ),
     rh_pial=dict(mandatory=True,
     ),
@@ -63,7 +64,7 @@ def test_ParcellationStats_inputs():
     terminal_output=dict(nohash=True,
     ),
     th3=dict(argstr='-th3',
-    requires=[u'cortex_label'],
+    requires=['cortex_label'],
     ),
     thickness=dict(mandatory=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ParseDICOMDir.py b/nipype/interfaces/freesurfer/tests/test_auto_ParseDICOMDir.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ParseDICOMDir.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ParseDICOMDir.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ParseDICOMDir
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_ReconAll.py b/nipype/interfaces/freesurfer/tests/test_auto_ReconAll.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_ReconAll.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_ReconAll.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ReconAll
 
 
@@ -26,6 +27,8 @@ def test_ReconAll_inputs():
     ),
     openmp=dict(argstr='-openmp %d',
     ),
+    parallel=dict(argstr='-parallel',
+    ),
     subject_id=dict(argstr='-subjid %s',
     usedefault=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Register.py b/nipype/interfaces/freesurfer/tests/test_auto_Register.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Register.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Register.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import Register
 
 
@@ -6,7 +7,7 @@ def test_Register_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
     curv=dict(argstr='-curv',
-    requires=[u'in_smoothwm'],
+    requires=['in_smoothwm'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RegisterAVItoTalairach.py b/nipype/interfaces/freesurfer/tests/test_auto_RegisterAVItoTalairach.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RegisterAVItoTalairach.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RegisterAVItoTalairach.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import RegisterAVItoTalairach
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RelabelHypointensities.py b/nipype/interfaces/freesurfer/tests/test_auto_RelabelHypointensities.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RelabelHypointensities.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RelabelHypointensities.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import RelabelHypointensities
 
 
@@ -21,7 +22,7 @@ def test_RelabelHypointensities_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'aseg'],
+    name_source=['aseg'],
     name_template='%s.hypos.mgz',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RemoveIntersection.py b/nipype/interfaces/freesurfer/tests/test_auto_RemoveIntersection.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RemoveIntersection.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RemoveIntersection.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import RemoveIntersection
 
 
@@ -19,7 +20,7 @@ def test_RemoveIntersection_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RemoveNeck.py b/nipype/interfaces/freesurfer/tests/test_auto_RemoveNeck.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RemoveNeck.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RemoveNeck.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import RemoveNeck
 
 
@@ -18,7 +19,7 @@ def test_RemoveNeck_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_noneck',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Resample.py b/nipype/interfaces/freesurfer/tests/test_auto_Resample.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Resample.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Resample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Resample
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RobustRegister.py b/nipype/interfaces/freesurfer/tests/test_auto_RobustRegister.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RobustRegister.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RobustRegister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import RobustRegister
 
 
@@ -7,7 +8,7 @@ def test_RobustRegister_inputs():
     ),
     auto_sens=dict(argstr='--satit',
     mandatory=True,
-    xor=[u'outlier_sens'],
+    xor=['outlier_sens'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -58,7 +59,7 @@ def test_RobustRegister_inputs():
     ),
     outlier_sens=dict(argstr='--sat %.4f',
     mandatory=True,
-    xor=[u'auto_sens'],
+    xor=['auto_sens'],
     ),
     registered_file=dict(argstr='--warp %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_RobustTemplate.py b/nipype/interfaces/freesurfer/tests/test_auto_RobustTemplate.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_RobustTemplate.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_RobustTemplate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..longitudinal import RobustTemplate
 
 
@@ -7,7 +8,7 @@ def test_RobustTemplate_inputs():
     ),
     auto_detect_sensitivity=dict(argstr='--satit',
     mandatory=True,
-    xor=[u'outlier_sensitivity'],
+    xor=['outlier_sensitivity'],
     ),
     average_metric=dict(argstr='--average %d',
     ),
@@ -38,7 +39,7 @@ def test_RobustTemplate_inputs():
     ),
     outlier_sensitivity=dict(argstr='--sat %.4f',
     mandatory=True,
-    xor=[u'auto_detect_sensitivity'],
+    xor=['auto_detect_sensitivity'],
     ),
     scaled_intensity_outputs=dict(argstr='--iscaleout %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SampleToSurface.py b/nipype/interfaces/freesurfer/tests/test_auto_SampleToSurface.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SampleToSurface.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SampleToSurface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SampleToSurface
 
 
@@ -10,7 +11,7 @@ def test_SampleToSurface_inputs():
     args=dict(argstr='%s',
     ),
     cortex_mask=dict(argstr='--cortex',
-    xor=[u'mask_label'],
+    xor=['mask_label'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -29,7 +30,7 @@ def test_SampleToSurface_inputs():
     hits_type=dict(argstr='--srchit_type',
     ),
     ico_order=dict(argstr='--icoorder %d',
-    requires=[u'target_subject'],
+    requires=['target_subject'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -37,14 +38,14 @@ def test_SampleToSurface_inputs():
     interp_method=dict(argstr='--interp %s',
     ),
     mask_label=dict(argstr='--mask %s',
-    xor=[u'cortex_mask'],
+    xor=['cortex_mask'],
     ),
     mni152reg=dict(argstr='--mni152reg',
     mandatory=True,
-    xor=[u'reg_file', u'reg_header', u'mni152reg'],
+    xor=['reg_file', 'reg_header', 'mni152reg'],
     ),
     no_reshape=dict(argstr='--noreshape',
-    xor=[u'reshape'],
+    xor=['reshape'],
     ),
     out_file=dict(argstr='--o %s',
     genfile=True,
@@ -52,31 +53,31 @@ def test_SampleToSurface_inputs():
     out_type=dict(argstr='--out_type %s',
     ),
     override_reg_subj=dict(argstr='--srcsubject %s',
-    requires=[u'subject_id'],
+    requires=['subject_id'],
     ),
     projection_stem=dict(mandatory=True,
-    xor=[u'sampling_method'],
+    xor=['sampling_method'],
     ),
     reference_file=dict(argstr='--ref %s',
     ),
     reg_file=dict(argstr='--reg %s',
     mandatory=True,
-    xor=[u'reg_file', u'reg_header', u'mni152reg'],
+    xor=['reg_file', 'reg_header', 'mni152reg'],
     ),
     reg_header=dict(argstr='--regheader %s',
     mandatory=True,
-    requires=[u'subject_id'],
-    xor=[u'reg_file', u'reg_header', u'mni152reg'],
+    requires=['subject_id'],
+    xor=['reg_file', 'reg_header', 'mni152reg'],
     ),
     reshape=dict(argstr='--reshape',
-    xor=[u'no_reshape'],
+    xor=['no_reshape'],
     ),
     reshape_slices=dict(argstr='--rf %d',
     ),
     sampling_method=dict(argstr='%s',
     mandatory=True,
-    requires=[u'sampling_range', u'sampling_units'],
-    xor=[u'projection_stem'],
+    requires=['sampling_range', 'sampling_units'],
+    xor=['projection_stem'],
     ),
     sampling_range=dict(),
     sampling_units=dict(),
@@ -92,7 +93,7 @@ def test_SampleToSurface_inputs():
     subject_id=dict(),
     subjects_dir=dict(),
     surf_reg=dict(argstr='--surfreg',
-    requires=[u'target_subject'],
+    requires=['target_subject'],
     ),
     surface=dict(argstr='--surf %s',
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SegStats.py b/nipype/interfaces/freesurfer/tests/test_auto_SegStats.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SegStats.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SegStats.py
@@ -1,11 +1,12 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import SegStats
 
 
 def test_SegStats_inputs():
     input_map = dict(annot=dict(argstr='--annot %s %s %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     args=dict(argstr='%s',
     ),
@@ -22,12 +23,12 @@ def test_SegStats_inputs():
     calc_snr=dict(argstr='--snr',
     ),
     color_table_file=dict(argstr='--ctab %s',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     cortex_vol_from_surf=dict(argstr='--surf-ctx-vol',
     ),
     default_color_table=dict(argstr='--ctab-default',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     empty=dict(argstr='--empty',
     ),
@@ -46,7 +47,7 @@ def test_SegStats_inputs():
     frame=dict(argstr='--frame %d',
     ),
     gca_color_table=dict(argstr='--ctab-gca %s',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -56,13 +57,13 @@ def test_SegStats_inputs():
     in_intensity=dict(argstr='--in %s --in-intensity-name %s',
     ),
     intensity_units=dict(argstr='--in-intensity-units %s',
-    requires=[u'in_intensity'],
+    requires=['in_intensity'],
     ),
     mask_erode=dict(argstr='--maskerode %d',
     ),
     mask_file=dict(argstr='--mask %s',
     ),
-    mask_frame=dict(requires=[u'mask_file'],
+    mask_frame=dict(requires=['mask_file'],
     ),
     mask_invert=dict(argstr='--maskinvert',
     ),
@@ -79,7 +80,7 @@ def test_SegStats_inputs():
     ),
     segmentation_file=dict(argstr='--seg %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     sf_avg_file=dict(argstr='--sfavg %s',
     ),
@@ -94,7 +95,7 @@ def test_SegStats_inputs():
     ),
     surf_label=dict(argstr='--slabel %s %s %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SegStatsReconAll.py b/nipype/interfaces/freesurfer/tests/test_auto_SegStatsReconAll.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SegStatsReconAll.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SegStatsReconAll.py
@@ -1,11 +1,12 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import SegStatsReconAll
 
 
 def test_SegStatsReconAll_inputs():
     input_map = dict(annot=dict(argstr='--annot %s %s %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     args=dict(argstr='%s',
     ),
@@ -23,13 +24,13 @@ def test_SegStatsReconAll_inputs():
     calc_snr=dict(argstr='--snr',
     ),
     color_table_file=dict(argstr='--ctab %s',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     copy_inputs=dict(),
     cortex_vol_from_surf=dict(argstr='--surf-ctx-vol',
     ),
     default_color_table=dict(argstr='--ctab-default',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     empty=dict(argstr='--empty',
     ),
@@ -48,7 +49,7 @@ def test_SegStatsReconAll_inputs():
     frame=dict(argstr='--frame %d',
     ),
     gca_color_table=dict(argstr='--ctab-gca %s',
-    xor=(u'color_table_file', u'default_color_table', u'gca_color_table'),
+    xor=('color_table_file', 'default_color_table', 'gca_color_table'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -58,7 +59,7 @@ def test_SegStatsReconAll_inputs():
     in_intensity=dict(argstr='--in %s --in-intensity-name %s',
     ),
     intensity_units=dict(argstr='--in-intensity-units %s',
-    requires=[u'in_intensity'],
+    requires=['in_intensity'],
     ),
     lh_orig_nofix=dict(mandatory=True,
     ),
@@ -70,7 +71,7 @@ def test_SegStatsReconAll_inputs():
     ),
     mask_file=dict(argstr='--mask %s',
     ),
-    mask_frame=dict(requires=[u'mask_file'],
+    mask_frame=dict(requires=['mask_file'],
     ),
     mask_invert=dict(argstr='--maskinvert',
     ),
@@ -96,7 +97,7 @@ def test_SegStatsReconAll_inputs():
     ),
     segmentation_file=dict(argstr='--seg %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     sf_avg_file=dict(argstr='--sfavg %s',
     ),
@@ -115,7 +116,7 @@ def test_SegStatsReconAll_inputs():
     ),
     surf_label=dict(argstr='--slabel %s %s %s',
     mandatory=True,
-    xor=(u'segmentation_file', u'annot', u'surf_label'),
+    xor=('segmentation_file', 'annot', 'surf_label'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SegmentCC.py b/nipype/interfaces/freesurfer/tests/test_auto_SegmentCC.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SegmentCC.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SegmentCC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SegmentCC
 
 
@@ -20,7 +21,7 @@ def test_SegmentCC_inputs():
     out_file=dict(argstr='-o %s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s.auto.mgz',
     ),
     out_rotation=dict(argstr='-lta %s',
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SegmentWM.py b/nipype/interfaces/freesurfer/tests/test_auto_SegmentWM.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SegmentWM.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SegmentWM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SegmentWM
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Smooth.py b/nipype/interfaces/freesurfer/tests/test_auto_Smooth.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Smooth.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Smooth.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Smooth
 
 
@@ -16,13 +17,13 @@ def test_Smooth_inputs():
     ),
     num_iters=dict(argstr='--niters %d',
     mandatory=True,
-    xor=[u'surface_fwhm'],
+    xor=['surface_fwhm'],
     ),
     proj_frac=dict(argstr='--projfrac %s',
-    xor=[u'proj_frac_avg'],
+    xor=['proj_frac_avg'],
     ),
     proj_frac_avg=dict(argstr='--projfrac-avg %.2f %.2f %.2f',
-    xor=[u'proj_frac'],
+    xor=['proj_frac'],
     ),
     reg_file=dict(argstr='--reg %s',
     mandatory=True,
@@ -33,8 +34,8 @@ def test_Smooth_inputs():
     subjects_dir=dict(),
     surface_fwhm=dict(argstr='--fwhm %f',
     mandatory=True,
-    requires=[u'reg_file'],
-    xor=[u'num_iters'],
+    requires=['reg_file'],
+    xor=['num_iters'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SmoothTessellation.py b/nipype/interfaces/freesurfer/tests/test_auto_SmoothTessellation.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SmoothTessellation.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SmoothTessellation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SmoothTessellation
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Sphere.py b/nipype/interfaces/freesurfer/tests/test_auto_Sphere.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Sphere.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Sphere.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Sphere
 
 
@@ -23,7 +24,7 @@ def test_Sphere_inputs():
     num_threads=dict(),
     out_file=dict(argstr='%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s.sphere',
     position=-1,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SphericalAverage.py b/nipype/interfaces/freesurfer/tests/test_auto_SphericalAverage.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SphericalAverage.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SphericalAverage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import SphericalAverage
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Surface2VolTransform.py b/nipype/interfaces/freesurfer/tests/test_auto_Surface2VolTransform.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Surface2VolTransform.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Surface2VolTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Surface2VolTransform
 
 
@@ -15,21 +16,21 @@ def test_Surface2VolTransform_inputs():
     usedefault=True,
     ),
     mkmask=dict(argstr='--mkmask',
-    xor=[u'source_file'],
+    xor=['source_file'],
     ),
     projfrac=dict(argstr='--projfrac %s',
     ),
     reg_file=dict(argstr='--volreg %s',
     mandatory=True,
-    xor=[u'subject_id'],
+    xor=['subject_id'],
     ),
     source_file=dict(argstr='--surfval %s',
     copyfile=False,
     mandatory=True,
-    xor=[u'mkmask'],
+    xor=['mkmask'],
     ),
     subject_id=dict(argstr='--identity %s',
-    xor=[u'reg_file'],
+    xor=['reg_file'],
     ),
     subjects_dir=dict(argstr='--sd %s',
     ),
@@ -41,12 +42,12 @@ def test_Surface2VolTransform_inputs():
     ),
     transformed_file=dict(argstr='--outvol %s',
     hash_files=False,
-    name_source=[u'source_file'],
+    name_source=['source_file'],
     name_template='%s_asVol.nii',
     ),
     vertexvol_file=dict(argstr='--vtxvol %s',
     hash_files=False,
-    name_source=[u'source_file'],
+    name_source=['source_file'],
     name_template='%s_asVol_vertex.nii',
     ),
     )
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSmooth.py b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSmooth.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSmooth.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSmooth.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SurfaceSmooth
 
 
@@ -12,7 +13,7 @@ def test_SurfaceSmooth_inputs():
     usedefault=True,
     ),
     fwhm=dict(argstr='--fwhm %.4f',
-    xor=[u'smooth_iters'],
+    xor=['smooth_iters'],
     ),
     hemi=dict(argstr='--hemi %s',
     mandatory=True,
@@ -29,7 +30,7 @@ def test_SurfaceSmooth_inputs():
     reshape=dict(argstr='--reshape',
     ),
     smooth_iters=dict(argstr='--smooth %d',
-    xor=[u'fwhm'],
+    xor=['fwhm'],
     ),
     subject_id=dict(argstr='--s %s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSnapshots.py b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSnapshots.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSnapshots.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceSnapshots.py
@@ -1,13 +1,14 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SurfaceSnapshots
 
 
 def test_SurfaceSnapshots_inputs():
     input_map = dict(annot_file=dict(argstr='-annotation %s',
-    xor=[u'annot_name'],
+    xor=['annot_name'],
     ),
     annot_name=dict(argstr='-annotation %s',
-    xor=[u'annot_file'],
+    xor=['annot_file'],
     ),
     args=dict(argstr='%s',
     ),
@@ -23,7 +24,7 @@ def test_SurfaceSnapshots_inputs():
     position=2,
     ),
     identity_reg=dict(argstr='-overlay-reg-identity',
-    xor=[u'overlay_reg', u'identity_reg', u'mni152_reg'],
+    xor=['overlay_reg', 'identity_reg', 'mni152_reg'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -31,29 +32,29 @@ def test_SurfaceSnapshots_inputs():
     invert_overlay=dict(argstr='-invphaseflag 1',
     ),
     label_file=dict(argstr='-label %s',
-    xor=[u'label_name'],
+    xor=['label_name'],
     ),
     label_name=dict(argstr='-label %s',
-    xor=[u'label_file'],
+    xor=['label_file'],
     ),
     label_outline=dict(argstr='-label-outline',
     ),
     label_under=dict(argstr='-labels-under',
     ),
     mni152_reg=dict(argstr='-mni152reg',
-    xor=[u'overlay_reg', u'identity_reg', u'mni152_reg'],
+    xor=['overlay_reg', 'identity_reg', 'mni152_reg'],
     ),
     orig_suffix=dict(argstr='-orig %s',
     ),
     overlay=dict(argstr='-overlay %s',
-    requires=[u'overlay_range'],
+    requires=['overlay_range'],
     ),
     overlay_range=dict(argstr='%s',
     ),
     overlay_range_offset=dict(argstr='-foffset %.3f',
     ),
     overlay_reg=dict(argstr='-overlay-reg %s',
-    xor=[u'overlay_reg', u'identity_reg', u'mni152_reg'],
+    xor=['overlay_reg', 'identity_reg', 'mni152_reg'],
     ),
     patch_file=dict(argstr='-patch %s',
     ),
@@ -65,15 +66,15 @@ def test_SurfaceSnapshots_inputs():
     show_color_text=dict(argstr='-colscaletext 1',
     ),
     show_curv=dict(argstr='-curv',
-    xor=[u'show_gray_curv'],
+    xor=['show_gray_curv'],
     ),
     show_gray_curv=dict(argstr='-gray',
-    xor=[u'show_curv'],
+    xor=['show_curv'],
     ),
     six_images=dict(),
     sphere_suffix=dict(argstr='-sphere %s',
     ),
-    stem_template_args=dict(requires=[u'screenshot_stem'],
+    stem_template_args=dict(requires=['screenshot_stem'],
     ),
     subject_id=dict(argstr='%s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceTransform.py b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceTransform.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SurfaceTransform.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SurfaceTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SurfaceTransform
 
 
@@ -23,17 +24,17 @@ def test_SurfaceTransform_inputs():
     ),
     source_annot_file=dict(argstr='--sval-annot %s',
     mandatory=True,
-    xor=[u'source_file'],
+    xor=['source_file'],
     ),
     source_file=dict(argstr='--sval %s',
     mandatory=True,
-    xor=[u'source_annot_file'],
+    xor=['source_annot_file'],
     ),
     source_subject=dict(argstr='--srcsubject %s',
     mandatory=True,
     ),
     source_type=dict(argstr='--sfmt %s',
-    requires=[u'source_file'],
+    requires=['source_file'],
     ),
     subjects_dir=dict(),
     target_ico_order=dict(argstr='--trgicoorder %d',
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_SynthesizeFLASH.py b/nipype/interfaces/freesurfer/tests/test_auto_SynthesizeFLASH.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_SynthesizeFLASH.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_SynthesizeFLASH.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SynthesizeFLASH
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_TalairachAVI.py b/nipype/interfaces/freesurfer/tests/test_auto_TalairachAVI.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_TalairachAVI.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_TalairachAVI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TalairachAVI
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_TalairachQC.py b/nipype/interfaces/freesurfer/tests/test_auto_TalairachQC.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_TalairachQC.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_TalairachQC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TalairachQC
 
 
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_Tkregister2.py b/nipype/interfaces/freesurfer/tests/test_auto_Tkregister2.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_Tkregister2.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_Tkregister2.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Tkregister2
 
 
@@ -13,10 +14,10 @@ def test_Tkregister2_inputs():
     fsl_out=dict(argstr='--fslregout %s',
     ),
     fstal=dict(argstr='--fstal',
-    xor=[u'target_image', u'moving_image'],
+    xor=['target_image', 'moving_image'],
     ),
     fstarg=dict(argstr='--fstarg',
-    xor=[u'target_image'],
+    xor=['target_image'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -39,7 +40,7 @@ def test_Tkregister2_inputs():
     ),
     subjects_dir=dict(),
     target_image=dict(argstr='--targ %s',
-    xor=[u'fstarg'],
+    xor=['fstarg'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_UnpackSDICOMDir.py b/nipype/interfaces/freesurfer/tests/test_auto_UnpackSDICOMDir.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_UnpackSDICOMDir.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_UnpackSDICOMDir.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import UnpackSDICOMDir
 
 
@@ -7,7 +8,7 @@ def test_UnpackSDICOMDir_inputs():
     ),
     config=dict(argstr='-cfg %s',
     mandatory=True,
-    xor=(u'run_info', u'config', u'seq_config'),
+    xor=('run_info', 'config', 'seq_config'),
     ),
     dir_structure=dict(argstr='-%s',
     ),
@@ -27,13 +28,13 @@ def test_UnpackSDICOMDir_inputs():
     ),
     run_info=dict(argstr='-run %d %s %s %s',
     mandatory=True,
-    xor=(u'run_info', u'config', u'seq_config'),
+    xor=('run_info', 'config', 'seq_config'),
     ),
     scan_only=dict(argstr='-scanonly %s',
     ),
     seq_config=dict(argstr='-seqcfg %s',
     mandatory=True,
-    xor=(u'run_info', u'config', u'seq_config'),
+    xor=('run_info', 'config', 'seq_config'),
     ),
     source_dir=dict(argstr='-src %s',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_VolumeMask.py b/nipype/interfaces/freesurfer/tests/test_auto_VolumeMask.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_VolumeMask.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_VolumeMask.py
@@ -1,11 +1,12 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import VolumeMask
 
 
 def test_VolumeMask_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
-    aseg=dict(xor=[u'in_aseg'],
+    aseg=dict(xor=['in_aseg'],
     ),
     copy_inputs=dict(),
     environ=dict(nohash=True,
@@ -15,7 +16,7 @@ def test_VolumeMask_inputs():
     usedefault=True,
     ),
     in_aseg=dict(argstr='--aseg_name %s',
-    xor=[u'aseg'],
+    xor=['aseg'],
     ),
     left_ribbonlabel=dict(argstr='--label_left_ribbon %d',
     mandatory=True,
diff --git a/nipype/interfaces/freesurfer/tests/test_auto_WatershedSkullStrip.py b/nipype/interfaces/freesurfer/tests/test_auto_WatershedSkullStrip.py
--- a/nipype/interfaces/freesurfer/tests/test_auto_WatershedSkullStrip.py
+++ b/nipype/interfaces/freesurfer/tests/test_auto_WatershedSkullStrip.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import WatershedSkullStrip
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ApplyMask.py b/nipype/interfaces/fsl/tests/test_auto_ApplyMask.py
--- a/nipype/interfaces/fsl/tests/test_auto_ApplyMask.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ApplyMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import ApplyMask
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ApplyTOPUP.py b/nipype/interfaces/fsl/tests/test_auto_ApplyTOPUP.py
--- a/nipype/interfaces/fsl/tests/test_auto_ApplyTOPUP.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ApplyTOPUP.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import ApplyTOPUP
 
 
@@ -25,17 +26,17 @@ def test_ApplyTOPUP_inputs():
     ),
     in_topup_fieldcoef=dict(argstr='--topup=%s',
     copyfile=False,
-    requires=[u'in_topup_movpar'],
+    requires=['in_topup_movpar'],
     ),
     in_topup_movpar=dict(copyfile=False,
-    requires=[u'in_topup_fieldcoef'],
+    requires=['in_topup_fieldcoef'],
     ),
     interp=dict(argstr='--interp=%s',
     ),
     method=dict(argstr='--method=%s',
     ),
     out_corrected=dict(argstr='--out=%s',
-    name_source=[u'in_files'],
+    name_source=['in_files'],
     name_template='%s_corrected',
     ),
     output_type=dict(),
diff --git a/nipype/interfaces/fsl/tests/test_auto_ApplyWarp.py b/nipype/interfaces/fsl/tests/test_auto_ApplyWarp.py
--- a/nipype/interfaces/fsl/tests/test_auto_ApplyWarp.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ApplyWarp.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ApplyWarp
 
 
 def test_ApplyWarp_inputs():
     input_map = dict(abswarp=dict(argstr='--abs',
-    xor=[u'relwarp'],
+    xor=['relwarp'],
     ),
     args=dict(argstr='%s',
     ),
@@ -43,7 +44,7 @@ def test_ApplyWarp_inputs():
     ),
     relwarp=dict(argstr='--rel',
     position=-1,
-    xor=[u'abswarp'],
+    xor=['abswarp'],
     ),
     superlevel=dict(argstr='--superlevel=%s',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_ApplyXFM.py b/nipype/interfaces/fsl/tests/test_auto_ApplyXFM.py
new file mode 100644
--- /dev/null
+++ b/nipype/interfaces/fsl/tests/test_auto_ApplyXFM.py
@@ -0,0 +1,164 @@
+# AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
+from ..preprocess import ApplyXFM
+
+
+def test_ApplyXFM_inputs():
+    input_map = dict(angle_rep=dict(argstr='-anglerep %s',
+    ),
+    apply_isoxfm=dict(argstr='-applyisoxfm %f',
+    xor=['apply_xfm'],
+    ),
+    apply_xfm=dict(argstr='-applyxfm',
+    requires=['in_matrix_file'],
+    usedefault=True,
+    ),
+    args=dict(argstr='%s',
+    ),
+    bbrslope=dict(argstr='-bbrslope %f',
+    min_ver='5.0.0',
+    ),
+    bbrtype=dict(argstr='-bbrtype %s',
+    min_ver='5.0.0',
+    ),
+    bgvalue=dict(argstr='-setbackground %f',
+    ),
+    bins=dict(argstr='-bins %d',
+    ),
+    coarse_search=dict(argstr='-coarsesearch %d',
+    units='degrees',
+    ),
+    cost=dict(argstr='-cost %s',
+    ),
+    cost_func=dict(argstr='-searchcost %s',
+    ),
+    datatype=dict(argstr='-datatype %s',
+    ),
+    display_init=dict(argstr='-displayinit',
+    ),
+    dof=dict(argstr='-dof %d',
+    ),
+    echospacing=dict(argstr='-echospacing %f',
+    min_ver='5.0.0',
+    ),
+    environ=dict(nohash=True,
+    usedefault=True,
+    ),
+    fieldmap=dict(argstr='-fieldmap %s',
+    min_ver='5.0.0',
+    ),
+    fieldmapmask=dict(argstr='-fieldmapmask %s',
+    min_ver='5.0.0',
+    ),
+    fine_search=dict(argstr='-finesearch %d',
+    units='degrees',
+    ),
+    force_scaling=dict(argstr='-forcescaling',
+    ),
+    ignore_exception=dict(nohash=True,
+    usedefault=True,
+    ),
+    in_file=dict(argstr='-in %s',
+    mandatory=True,
+    position=0,
+    ),
+    in_matrix_file=dict(argstr='-init %s',
+    ),
+    in_weight=dict(argstr='-inweight %s',
+    ),
+    interp=dict(argstr='-interp %s',
+    ),
+    min_sampling=dict(argstr='-minsampling %f',
+    units='mm',
+    ),
+    no_clamp=dict(argstr='-noclamp',
+    ),
+    no_resample=dict(argstr='-noresample',
+    ),
+    no_resample_blur=dict(argstr='-noresampblur',
+    ),
+    no_search=dict(argstr='-nosearch',
+    ),
+    out_file=dict(argstr='-out %s',
+    hash_files=False,
+    name_source=['in_file'],
+    name_template='%s_flirt',
+    position=2,
+    ),
+    out_log=dict(keep_extension=True,
+    name_source=['in_file'],
+    name_template='%s_flirt.log',
+    requires=['save_log'],
+    ),
+    out_matrix_file=dict(argstr='-omat %s',
+    hash_files=False,
+    keep_extension=True,
+    name_source=['in_file'],
+    name_template='%s_flirt.mat',
+    position=3,
+    ),
+    output_type=dict(),
+    padding_size=dict(argstr='-paddingsize %d',
+    units='voxels',
+    ),
+    pedir=dict(argstr='-pedir %d',
+    min_ver='5.0.0',
+    ),
+    ref_weight=dict(argstr='-refweight %s',
+    ),
+    reference=dict(argstr='-ref %s',
+    mandatory=True,
+    position=1,
+    ),
+    rigid2D=dict(argstr='-2D',
+    ),
+    save_log=dict(),
+    schedule=dict(argstr='-schedule %s',
+    ),
+    searchr_x=dict(argstr='-searchrx %s',
+    units='degrees',
+    ),
+    searchr_y=dict(argstr='-searchry %s',
+    units='degrees',
+    ),
+    searchr_z=dict(argstr='-searchrz %s',
+    units='degrees',
+    ),
+    sinc_width=dict(argstr='-sincwidth %d',
+    units='voxels',
+    ),
+    sinc_window=dict(argstr='-sincwindow %s',
+    ),
+    terminal_output=dict(nohash=True,
+    ),
+    uses_qform=dict(argstr='-usesqform',
+    ),
+    verbose=dict(argstr='-verbose %d',
+    ),
+    wm_seg=dict(argstr='-wmseg %s',
+    min_ver='5.0.0',
+    ),
+    wmcoords=dict(argstr='-wmcoords %s',
+    min_ver='5.0.0',
+    ),
+    wmnorms=dict(argstr='-wmnorms %s',
+    min_ver='5.0.0',
+    ),
+    )
+    inputs = ApplyXFM.input_spec()
+
+    for key, metadata in list(input_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(inputs.traits()[key], metakey) == value
+
+
+def test_ApplyXFM_outputs():
+    output_map = dict(out_file=dict(),
+    out_log=dict(),
+    out_matrix_file=dict(),
+    )
+    outputs = ApplyXFM.output_spec()
+
+    for key, metadata in list(output_map.items()):
+        for metakey, value in list(metadata.items()):
+            assert getattr(outputs.traits()[key], metakey) == value
diff --git a/nipype/interfaces/fsl/tests/test_auto_ApplyXfm.py b/nipype/interfaces/fsl/tests/test_auto_ApplyXfm.py
--- a/nipype/interfaces/fsl/tests/test_auto_ApplyXfm.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ApplyXfm.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ApplyXfm
 
 
@@ -6,10 +7,10 @@ def test_ApplyXfm_inputs():
     input_map = dict(angle_rep=dict(argstr='-anglerep %s',
     ),
     apply_isoxfm=dict(argstr='-applyisoxfm %f',
-    xor=[u'apply_xfm'],
+    xor=['apply_xfm'],
     ),
     apply_xfm=dict(argstr='-applyxfm',
-    requires=[u'in_matrix_file'],
+    requires=['in_matrix_file'],
     usedefault=True,
     ),
     args=dict(argstr='%s',
@@ -80,19 +81,19 @@ def test_ApplyXfm_inputs():
     ),
     out_file=dict(argstr='-out %s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt',
     position=2,
     ),
     out_log=dict(keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt.log',
-    requires=[u'save_log'],
+    requires=['save_log'],
     ),
     out_matrix_file=dict(argstr='-omat %s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt.mat',
     position=3,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_AvScale.py b/nipype/interfaces/fsl/tests/test_auto_AvScale.py
--- a/nipype/interfaces/fsl/tests/test_auto_AvScale.py
+++ b/nipype/interfaces/fsl/tests/test_auto_AvScale.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import AvScale
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_B0Calc.py b/nipype/interfaces/fsl/tests/test_auto_B0Calc.py
--- a/nipype/interfaces/fsl/tests/test_auto_B0Calc.py
+++ b/nipype/interfaces/fsl/tests/test_auto_B0Calc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..possum import B0Calc
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_BEDPOSTX5.py b/nipype/interfaces/fsl/tests/test_auto_BEDPOSTX5.py
--- a/nipype/interfaces/fsl/tests/test_auto_BEDPOSTX5.py
+++ b/nipype/interfaces/fsl/tests/test_auto_BEDPOSTX5.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import BEDPOSTX5
 
 
 def test_BEDPOSTX5_inputs():
     input_map = dict(all_ard=dict(argstr='--allard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     args=dict(argstr='%s',
     ),
@@ -17,7 +18,7 @@ def test_BEDPOSTX5_inputs():
     bvecs=dict(mandatory=True,
     ),
     cnlinear=dict(argstr='--cnonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     dwi=dict(mandatory=True,
     ),
@@ -25,10 +26,10 @@ def test_BEDPOSTX5_inputs():
     usedefault=True,
     ),
     f0_ard=dict(argstr='--f0 --ardf0',
-    xor=[u'f0_noard', u'f0_ard', u'all_ard'],
+    xor=['f0_noard', 'f0_ard', 'all_ard'],
     ),
     f0_noard=dict(argstr='--f0',
-    xor=[u'f0_noard', u'f0_ard'],
+    xor=['f0_noard', 'f0_ard'],
     ),
     force_dir=dict(argstr='--forcedir',
     usedefault=True,
@@ -54,13 +55,13 @@ def test_BEDPOSTX5_inputs():
     n_jumps=dict(argstr='-j %d',
     ),
     no_ard=dict(argstr='--noard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     no_spat=dict(argstr='--nospat',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     non_linear=dict(argstr='--nonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     out_dir=dict(argstr='%s',
     mandatory=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_BET.py b/nipype/interfaces/fsl/tests/test_auto_BET.py
--- a/nipype/interfaces/fsl/tests/test_auto_BET.py
+++ b/nipype/interfaces/fsl/tests/test_auto_BET.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import BET
 
 
@@ -14,7 +15,7 @@ def test_BET_inputs():
     frac=dict(argstr='-f %.2f',
     ),
     functional=dict(argstr='-F',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -38,27 +39,27 @@ def test_BET_inputs():
     ),
     output_type=dict(),
     padding=dict(argstr='-Z',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     radius=dict(argstr='-r %d',
     units='mm',
     ),
     reduce_bias=dict(argstr='-B',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     remove_eyes=dict(argstr='-S',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     robust=dict(argstr='-R',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     skull=dict(argstr='-s',
     ),
     surfaces=dict(argstr='-A',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     t2_guided=dict(argstr='-A2 %s',
-    xor=(u'functional', u'reduce_bias', u'robust', u'padding', u'remove_eyes', u'surfaces', u't2_guided'),
+    xor=('functional', 'reduce_bias', 'robust', 'padding', 'remove_eyes', 'surfaces', 't2_guided'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_BinaryMaths.py b/nipype/interfaces/fsl/tests/test_auto_BinaryMaths.py
--- a/nipype/interfaces/fsl/tests/test_auto_BinaryMaths.py
+++ b/nipype/interfaces/fsl/tests/test_auto_BinaryMaths.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import BinaryMaths
 
 
@@ -24,12 +25,12 @@ def test_BinaryMaths_inputs():
     operand_file=dict(argstr='%s',
     mandatory=True,
     position=5,
-    xor=[u'operand_value'],
+    xor=['operand_value'],
     ),
     operand_value=dict(argstr='%.8f',
     mandatory=True,
     position=5,
-    xor=[u'operand_file'],
+    xor=['operand_file'],
     ),
     operation=dict(argstr='-%s',
     mandatory=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_ChangeDataType.py b/nipype/interfaces/fsl/tests/test_auto_ChangeDataType.py
--- a/nipype/interfaces/fsl/tests/test_auto_ChangeDataType.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ChangeDataType.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import ChangeDataType
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Cluster.py b/nipype/interfaces/fsl/tests/test_auto_Cluster.py
--- a/nipype/interfaces/fsl/tests/test_auto_Cluster.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Cluster.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Cluster
 
 
@@ -62,7 +63,7 @@ def test_Cluster_inputs():
     peak_distance=dict(argstr='--peakdist=%.10f',
     ),
     pthreshold=dict(argstr='--pthresh=%.10f',
-    requires=[u'dlh', u'volume'],
+    requires=['dlh', 'volume'],
     ),
     std_space_file=dict(argstr='--stdvol=%s',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_Complex.py b/nipype/interfaces/fsl/tests/test_auto_Complex.py
--- a/nipype/interfaces/fsl/tests/test_auto_Complex.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Complex.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Complex
 
 
@@ -7,7 +8,7 @@ def test_Complex_inputs():
     ),
     complex_cartesian=dict(argstr='-complex',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     complex_in_file=dict(argstr='%s',
     position=2,
@@ -17,20 +18,20 @@ def test_Complex_inputs():
     ),
     complex_merge=dict(argstr='-complexmerge',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge', u'start_vol', u'end_vol'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge', 'start_vol', 'end_vol'],
     ),
     complex_out_file=dict(argstr='%s',
     genfile=True,
     position=-3,
-    xor=[u'complex_out_file', u'magnitude_out_file', u'phase_out_file', u'real_out_file', u'imaginary_out_file', u'real_polar', u'real_cartesian'],
+    xor=['complex_out_file', 'magnitude_out_file', 'phase_out_file', 'real_out_file', 'imaginary_out_file', 'real_polar', 'real_cartesian'],
     ),
     complex_polar=dict(argstr='-complexpolar',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     complex_split=dict(argstr='-complexsplit',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     end_vol=dict(argstr='%d',
     position=-1,
@@ -47,7 +48,7 @@ def test_Complex_inputs():
     imaginary_out_file=dict(argstr='%s',
     genfile=True,
     position=-3,
-    xor=[u'complex_out_file', u'magnitude_out_file', u'phase_out_file', u'real_polar', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['complex_out_file', 'magnitude_out_file', 'phase_out_file', 'real_polar', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     magnitude_in_file=dict(argstr='%s',
     position=2,
@@ -55,7 +56,7 @@ def test_Complex_inputs():
     magnitude_out_file=dict(argstr='%s',
     genfile=True,
     position=-4,
-    xor=[u'complex_out_file', u'real_out_file', u'imaginary_out_file', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['complex_out_file', 'real_out_file', 'imaginary_out_file', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     output_type=dict(),
     phase_in_file=dict(argstr='%s',
@@ -64,11 +65,11 @@ def test_Complex_inputs():
     phase_out_file=dict(argstr='%s',
     genfile=True,
     position=-3,
-    xor=[u'complex_out_file', u'real_out_file', u'imaginary_out_file', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['complex_out_file', 'real_out_file', 'imaginary_out_file', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     real_cartesian=dict(argstr='-realcartesian',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     real_in_file=dict(argstr='%s',
     position=2,
@@ -76,11 +77,11 @@ def test_Complex_inputs():
     real_out_file=dict(argstr='%s',
     genfile=True,
     position=-4,
-    xor=[u'complex_out_file', u'magnitude_out_file', u'phase_out_file', u'real_polar', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['complex_out_file', 'magnitude_out_file', 'phase_out_file', 'real_polar', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     real_polar=dict(argstr='-realpolar',
     position=1,
-    xor=[u'real_polar', u'real_cartesian', u'complex_cartesian', u'complex_polar', u'complex_split', u'complex_merge'],
+    xor=['real_polar', 'real_cartesian', 'complex_cartesian', 'complex_polar', 'complex_split', 'complex_merge'],
     ),
     start_vol=dict(argstr='%d',
     position=-2,
diff --git a/nipype/interfaces/fsl/tests/test_auto_ContrastMgr.py b/nipype/interfaces/fsl/tests/test_auto_ContrastMgr.py
--- a/nipype/interfaces/fsl/tests/test_auto_ContrastMgr.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ContrastMgr.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import ContrastMgr
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ConvertWarp.py b/nipype/interfaces/fsl/tests/test_auto_ConvertWarp.py
--- a/nipype/interfaces/fsl/tests/test_auto_ConvertWarp.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ConvertWarp.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ConvertWarp
 
 
 def test_ConvertWarp_inputs():
     input_map = dict(abswarp=dict(argstr='--abs',
-    xor=[u'relwarp'],
+    xor=['relwarp'],
     ),
     args=dict(argstr='%s',
     ),
@@ -23,16 +24,16 @@ def test_ConvertWarp_inputs():
     midmat=dict(argstr='--midmat=%s',
     ),
     out_abswarp=dict(argstr='--absout',
-    xor=[u'out_relwarp'],
+    xor=['out_relwarp'],
     ),
     out_file=dict(argstr='--out=%s',
-    name_source=[u'reference'],
+    name_source=['reference'],
     name_template='%s_concatwarp',
     output_name='out_file',
     position=-1,
     ),
     out_relwarp=dict(argstr='--relout',
-    xor=[u'out_abswarp'],
+    xor=['out_abswarp'],
     ),
     output_type=dict(),
     postmat=dict(argstr='--postmat=%s',
@@ -44,10 +45,10 @@ def test_ConvertWarp_inputs():
     position=1,
     ),
     relwarp=dict(argstr='--rel',
-    xor=[u'abswarp'],
+    xor=['abswarp'],
     ),
     shift_direction=dict(argstr='--shiftdir=%s',
-    requires=[u'shift_in_file'],
+    requires=['shift_in_file'],
     ),
     shift_in_file=dict(argstr='--shiftmap=%s',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_ConvertXFM.py b/nipype/interfaces/fsl/tests/test_auto_ConvertXFM.py
--- a/nipype/interfaces/fsl/tests/test_auto_ConvertXFM.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ConvertXFM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ConvertXFM
 
 
@@ -7,16 +8,16 @@ def test_ConvertXFM_inputs():
     ),
     concat_xfm=dict(argstr='-concat',
     position=-3,
-    requires=[u'in_file2'],
-    xor=[u'invert_xfm', u'concat_xfm', u'fix_scale_skew'],
+    requires=['in_file2'],
+    xor=['invert_xfm', 'concat_xfm', 'fix_scale_skew'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
     ),
     fix_scale_skew=dict(argstr='-fixscaleskew',
     position=-3,
-    requires=[u'in_file2'],
-    xor=[u'invert_xfm', u'concat_xfm', u'fix_scale_skew'],
+    requires=['in_file2'],
+    xor=['invert_xfm', 'concat_xfm', 'fix_scale_skew'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -30,7 +31,7 @@ def test_ConvertXFM_inputs():
     ),
     invert_xfm=dict(argstr='-inverse',
     position=-3,
-    xor=[u'invert_xfm', u'concat_xfm', u'fix_scale_skew'],
+    xor=['invert_xfm', 'concat_xfm', 'fix_scale_skew'],
     ),
     out_file=dict(argstr='-omat %s',
     genfile=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_CopyGeom.py b/nipype/interfaces/fsl/tests/test_auto_CopyGeom.py
--- a/nipype/interfaces/fsl/tests/test_auto_CopyGeom.py
+++ b/nipype/interfaces/fsl/tests/test_auto_CopyGeom.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import CopyGeom
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_DTIFit.py b/nipype/interfaces/fsl/tests/test_auto_DTIFit.py
--- a/nipype/interfaces/fsl/tests/test_auto_DTIFit.py
+++ b/nipype/interfaces/fsl/tests/test_auto_DTIFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DTIFit
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_DilateImage.py b/nipype/interfaces/fsl/tests/test_auto_DilateImage.py
--- a/nipype/interfaces/fsl/tests/test_auto_DilateImage.py
+++ b/nipype/interfaces/fsl/tests/test_auto_DilateImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import DilateImage
 
 
@@ -20,14 +21,14 @@ def test_DilateImage_inputs():
     ),
     kernel_file=dict(argstr='%s',
     position=5,
-    xor=[u'kernel_size'],
+    xor=['kernel_size'],
     ),
     kernel_shape=dict(argstr='-kernel %s',
     position=4,
     ),
     kernel_size=dict(argstr='%.4f',
     position=5,
-    xor=[u'kernel_file'],
+    xor=['kernel_file'],
     ),
     nan2zeros=dict(argstr='-nan',
     position=3,
diff --git a/nipype/interfaces/fsl/tests/test_auto_DistanceMap.py b/nipype/interfaces/fsl/tests/test_auto_DistanceMap.py
--- a/nipype/interfaces/fsl/tests/test_auto_DistanceMap.py
+++ b/nipype/interfaces/fsl/tests/test_auto_DistanceMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import DistanceMap
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_EPIDeWarp.py b/nipype/interfaces/fsl/tests/test_auto_EPIDeWarp.py
--- a/nipype/interfaces/fsl/tests/test_auto_EPIDeWarp.py
+++ b/nipype/interfaces/fsl/tests/test_auto_EPIDeWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import EPIDeWarp
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Eddy.py b/nipype/interfaces/fsl/tests/test_auto_Eddy.py
--- a/nipype/interfaces/fsl/tests/test_auto_Eddy.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Eddy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import Eddy
 
 
@@ -72,7 +73,12 @@ def test_Eddy_inputs():
 
 def test_Eddy_outputs():
     output_map = dict(out_corrected=dict(),
+    out_movement_rms=dict(),
+    out_outlier_report=dict(),
     out_parameter=dict(),
+    out_restricted_movement_rms=dict(),
+    out_rotated_bvecs=dict(),
+    out_shell_alignment_parameters=dict(),
     )
     outputs = Eddy.output_spec()
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_EddyCorrect.py b/nipype/interfaces/fsl/tests/test_auto_EddyCorrect.py
--- a/nipype/interfaces/fsl/tests/test_auto_EddyCorrect.py
+++ b/nipype/interfaces/fsl/tests/test_auto_EddyCorrect.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import EddyCorrect
 
 
@@ -16,7 +17,7 @@ def test_EddyCorrect_inputs():
     position=0,
     ),
     out_file=dict(argstr='%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_edc',
     output_name='eddy_corrected',
     position=1,
diff --git a/nipype/interfaces/fsl/tests/test_auto_EpiReg.py b/nipype/interfaces/fsl/tests/test_auto_EpiReg.py
--- a/nipype/interfaces/fsl/tests/test_auto_EpiReg.py
+++ b/nipype/interfaces/fsl/tests/test_auto_EpiReg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import EpiReg
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ErodeImage.py b/nipype/interfaces/fsl/tests/test_auto_ErodeImage.py
--- a/nipype/interfaces/fsl/tests/test_auto_ErodeImage.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ErodeImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import ErodeImage
 
 
@@ -20,14 +21,14 @@ def test_ErodeImage_inputs():
     ),
     kernel_file=dict(argstr='%s',
     position=5,
-    xor=[u'kernel_size'],
+    xor=['kernel_size'],
     ),
     kernel_shape=dict(argstr='-kernel %s',
     position=4,
     ),
     kernel_size=dict(argstr='%.4f',
     position=5,
-    xor=[u'kernel_file'],
+    xor=['kernel_file'],
     ),
     minimum_filter=dict(argstr='%s',
     position=6,
diff --git a/nipype/interfaces/fsl/tests/test_auto_ExtractROI.py b/nipype/interfaces/fsl/tests/test_auto_ExtractROI.py
--- a/nipype/interfaces/fsl/tests/test_auto_ExtractROI.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ExtractROI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ExtractROI
 
 
@@ -7,7 +8,7 @@ def test_ExtractROI_inputs():
     ),
     crop_list=dict(argstr='%s',
     position=2,
-    xor=[u'x_min', u'x_size', u'y_min', u'y_size', u'z_min', u'z_size', u't_min', u't_size'],
+    xor=['x_min', 'x_size', 'y_min', 'y_size', 'z_min', 'z_size', 't_min', 't_size'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_FAST.py b/nipype/interfaces/fsl/tests/test_auto_FAST.py
--- a/nipype/interfaces/fsl/tests/test_auto_FAST.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FAST.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FAST
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FEAT.py b/nipype/interfaces/fsl/tests/test_auto_FEAT.py
--- a/nipype/interfaces/fsl/tests/test_auto_FEAT.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FEAT.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FEAT
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FEATModel.py b/nipype/interfaces/fsl/tests/test_auto_FEATModel.py
--- a/nipype/interfaces/fsl/tests/test_auto_FEATModel.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FEATModel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FEATModel
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FEATRegister.py b/nipype/interfaces/fsl/tests/test_auto_FEATRegister.py
--- a/nipype/interfaces/fsl/tests/test_auto_FEATRegister.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FEATRegister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FEATRegister
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FIRST.py b/nipype/interfaces/fsl/tests/test_auto_FIRST.py
--- a/nipype/interfaces/fsl/tests/test_auto_FIRST.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FIRST.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FIRST
 
 
@@ -29,7 +30,7 @@ def test_FIRST_inputs():
     method=dict(argstr='-m %s',
     position=4,
     usedefault=True,
-    xor=[u'method_as_numerical_threshold'],
+    xor=['method_as_numerical_threshold'],
     ),
     method_as_numerical_threshold=dict(argstr='-m %.4f',
     position=4,
diff --git a/nipype/interfaces/fsl/tests/test_auto_FLAMEO.py b/nipype/interfaces/fsl/tests/test_auto_FLAMEO.py
--- a/nipype/interfaces/fsl/tests/test_auto_FLAMEO.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FLAMEO.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FLAMEO
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FLIRT.py b/nipype/interfaces/fsl/tests/test_auto_FLIRT.py
--- a/nipype/interfaces/fsl/tests/test_auto_FLIRT.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FLIRT.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FLIRT
 
 
@@ -6,10 +7,10 @@ def test_FLIRT_inputs():
     input_map = dict(angle_rep=dict(argstr='-anglerep %s',
     ),
     apply_isoxfm=dict(argstr='-applyisoxfm %f',
-    xor=[u'apply_xfm'],
+    xor=['apply_xfm'],
     ),
     apply_xfm=dict(argstr='-applyxfm',
-    requires=[u'in_matrix_file'],
+    requires=['in_matrix_file'],
     ),
     args=dict(argstr='%s',
     ),
@@ -79,19 +80,19 @@ def test_FLIRT_inputs():
     ),
     out_file=dict(argstr='-out %s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt',
     position=2,
     ),
     out_log=dict(keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt.log',
-    requires=[u'save_log'],
+    requires=['save_log'],
     ),
     out_matrix_file=dict(argstr='-omat %s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_flirt.mat',
     position=3,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_FNIRT.py b/nipype/interfaces/fsl/tests/test_auto_FNIRT.py
--- a/nipype/interfaces/fsl/tests/test_auto_FNIRT.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FNIRT.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FNIRT
 
 
@@ -7,15 +8,15 @@ def test_FNIRT_inputs():
     ),
     apply_inmask=dict(argstr='--applyinmask=%s',
     sep=',',
-    xor=[u'skip_inmask'],
+    xor=['skip_inmask'],
     ),
     apply_intensity_mapping=dict(argstr='--estint=%s',
     sep=',',
-    xor=[u'skip_intensity_mapping'],
+    xor=['skip_intensity_mapping'],
     ),
     apply_refmask=dict(argstr='--applyrefmask=%s',
     sep=',',
-    xor=[u'skip_refmask'],
+    xor=['skip_refmask'],
     ),
     args=dict(argstr='%s',
     ),
@@ -47,6 +48,7 @@ def test_FNIRT_inputs():
     sep=',',
     ),
     in_intensitymap_file=dict(argstr='--intin=%s',
+    copyfiles=False,
     ),
     inmask_file=dict(argstr='--inmask=%s',
     ),
@@ -97,15 +99,15 @@ def test_FNIRT_inputs():
     skip_implicit_ref_masking=dict(argstr='--imprefm=0',
     ),
     skip_inmask=dict(argstr='--applyinmask=0',
-    xor=[u'apply_inmask'],
+    xor=['apply_inmask'],
     ),
     skip_intensity_mapping=dict(argstr='--estint=0',
-    xor=[u'apply_intensity_mapping'],
+    xor=['apply_intensity_mapping'],
     ),
     skip_lambda_ssq=dict(argstr='--ssqlambda=0',
     ),
     skip_refmask=dict(argstr='--applyrefmask=0',
-    xor=[u'apply_refmask'],
+    xor=['apply_refmask'],
     ),
     spline_order=dict(argstr='--splineorder=%d',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_FSLCommand.py b/nipype/interfaces/fsl/tests/test_auto_FSLCommand.py
--- a/nipype/interfaces/fsl/tests/test_auto_FSLCommand.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FSLCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import FSLCommand
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_FSLXCommand.py b/nipype/interfaces/fsl/tests/test_auto_FSLXCommand.py
--- a/nipype/interfaces/fsl/tests/test_auto_FSLXCommand.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FSLXCommand.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import FSLXCommand
 
 
 def test_FSLXCommand_inputs():
     input_map = dict(all_ard=dict(argstr='--allard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     args=dict(argstr='%s',
     ),
@@ -19,7 +20,7 @@ def test_FSLXCommand_inputs():
     mandatory=True,
     ),
     cnlinear=dict(argstr='--cnonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     dwi=dict(argstr='--data=%s',
     mandatory=True,
@@ -28,10 +29,10 @@ def test_FSLXCommand_inputs():
     usedefault=True,
     ),
     f0_ard=dict(argstr='--f0 --ardf0',
-    xor=[u'f0_noard', u'f0_ard', u'all_ard'],
+    xor=['f0_noard', 'f0_ard', 'all_ard'],
     ),
     f0_noard=dict(argstr='--f0',
-    xor=[u'f0_noard', u'f0_ard'],
+    xor=['f0_noard', 'f0_ard'],
     ),
     force_dir=dict(argstr='--forcedir',
     usedefault=True,
@@ -56,13 +57,13 @@ def test_FSLXCommand_inputs():
     n_jumps=dict(argstr='--njumps=%d',
     ),
     no_ard=dict(argstr='--noard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     no_spat=dict(argstr='--nospat',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     non_linear=dict(argstr='--nonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     output_type=dict(),
     rician=dict(argstr='--rician',
diff --git a/nipype/interfaces/fsl/tests/test_auto_FUGUE.py b/nipype/interfaces/fsl/tests/test_auto_FUGUE.py
--- a/nipype/interfaces/fsl/tests/test_auto_FUGUE.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FUGUE.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FUGUE
 
 
@@ -27,10 +28,10 @@ def test_FUGUE_inputs():
     fourier_order=dict(argstr='--fourier=%d',
     ),
     icorr=dict(argstr='--icorr',
-    requires=[u'shift_in_file'],
+    requires=['shift_in_file'],
     ),
     icorr_only=dict(argstr='--icorronly',
-    requires=[u'unwarped_file'],
+    requires=['unwarped_file'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -56,15 +57,15 @@ def test_FUGUE_inputs():
     ),
     poly_order=dict(argstr='--poly=%d',
     ),
-    save_fmap=dict(xor=[u'save_unmasked_fmap'],
+    save_fmap=dict(xor=['save_unmasked_fmap'],
     ),
-    save_shift=dict(xor=[u'save_unmasked_shift'],
+    save_shift=dict(xor=['save_unmasked_shift'],
     ),
     save_unmasked_fmap=dict(argstr='--unmaskfmap',
-    xor=[u'save_fmap'],
+    xor=['save_fmap'],
     ),
     save_unmasked_shift=dict(argstr='--unmaskshift',
-    xor=[u'save_shift'],
+    xor=['save_shift'],
     ),
     shift_in_file=dict(argstr='--loadshift=%s',
     ),
@@ -79,12 +80,12 @@ def test_FUGUE_inputs():
     unwarp_direction=dict(argstr='--unwarpdir=%s',
     ),
     unwarped_file=dict(argstr='--unwarp=%s',
-    requires=[u'in_file'],
-    xor=[u'warped_file'],
+    requires=['in_file'],
+    xor=['warped_file'],
     ),
     warped_file=dict(argstr='--warp=%s',
-    requires=[u'in_file'],
-    xor=[u'unwarped_file'],
+    requires=['in_file'],
+    xor=['unwarped_file'],
     ),
     )
     inputs = FUGUE.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_FilterRegressor.py b/nipype/interfaces/fsl/tests/test_auto_FilterRegressor.py
--- a/nipype/interfaces/fsl/tests/test_auto_FilterRegressor.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FilterRegressor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import FilterRegressor
 
 
@@ -15,12 +16,12 @@ def test_FilterRegressor_inputs():
     filter_all=dict(argstr="-f '%s'",
     mandatory=True,
     position=4,
-    xor=[u'filter_columns'],
+    xor=['filter_columns'],
     ),
     filter_columns=dict(argstr="-f '%s'",
     mandatory=True,
     position=4,
-    xor=[u'filter_all'],
+    xor=['filter_all'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_FindTheBiggest.py b/nipype/interfaces/fsl/tests/test_auto_FindTheBiggest.py
--- a/nipype/interfaces/fsl/tests/test_auto_FindTheBiggest.py
+++ b/nipype/interfaces/fsl/tests/test_auto_FindTheBiggest.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import FindTheBiggest
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_GLM.py b/nipype/interfaces/fsl/tests/test_auto_GLM.py
--- a/nipype/interfaces/fsl/tests/test_auto_GLM.py
+++ b/nipype/interfaces/fsl/tests/test_auto_GLM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import GLM
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ImageMaths.py b/nipype/interfaces/fsl/tests/test_auto_ImageMaths.py
--- a/nipype/interfaces/fsl/tests/test_auto_ImageMaths.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ImageMaths.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ImageMaths
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ImageMeants.py b/nipype/interfaces/fsl/tests/test_auto_ImageMeants.py
--- a/nipype/interfaces/fsl/tests/test_auto_ImageMeants.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ImageMeants.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ImageMeants
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ImageStats.py b/nipype/interfaces/fsl/tests/test_auto_ImageStats.py
--- a/nipype/interfaces/fsl/tests/test_auto_ImageStats.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ImageStats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ImageStats
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_InvWarp.py b/nipype/interfaces/fsl/tests/test_auto_InvWarp.py
--- a/nipype/interfaces/fsl/tests/test_auto_InvWarp.py
+++ b/nipype/interfaces/fsl/tests/test_auto_InvWarp.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import InvWarp
 
 
 def test_InvWarp_inputs():
     input_map = dict(absolute=dict(argstr='--abs',
-    xor=[u'relative'],
+    xor=['relative'],
     ),
     args=dict(argstr='%s',
     ),
@@ -16,7 +17,7 @@ def test_InvWarp_inputs():
     ),
     inverse_warp=dict(argstr='--out=%s',
     hash_files=False,
-    name_source=[u'warp'],
+    name_source=['warp'],
     name_template='%s_inverse',
     ),
     jacobian_max=dict(argstr='--jmax=%f',
@@ -34,7 +35,7 @@ def test_InvWarp_inputs():
     regularise=dict(argstr='--regularise=%f',
     ),
     relative=dict(argstr='--rel',
-    xor=[u'absolute'],
+    xor=['absolute'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_IsotropicSmooth.py b/nipype/interfaces/fsl/tests/test_auto_IsotropicSmooth.py
--- a/nipype/interfaces/fsl/tests/test_auto_IsotropicSmooth.py
+++ b/nipype/interfaces/fsl/tests/test_auto_IsotropicSmooth.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import IsotropicSmooth
 
 
@@ -11,7 +12,7 @@ def test_IsotropicSmooth_inputs():
     fwhm=dict(argstr='-s %.5f',
     mandatory=True,
     position=4,
-    xor=[u'sigma'],
+    xor=['sigma'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -38,7 +39,7 @@ def test_IsotropicSmooth_inputs():
     sigma=dict(argstr='-s %.5f',
     mandatory=True,
     position=4,
-    xor=[u'fwhm'],
+    xor=['fwhm'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_L2Model.py b/nipype/interfaces/fsl/tests/test_auto_L2Model.py
--- a/nipype/interfaces/fsl/tests/test_auto_L2Model.py
+++ b/nipype/interfaces/fsl/tests/test_auto_L2Model.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import L2Model
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Level1Design.py b/nipype/interfaces/fsl/tests/test_auto_Level1Design.py
--- a/nipype/interfaces/fsl/tests/test_auto_Level1Design.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Level1Design.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Level1Design
 
 
@@ -13,6 +14,8 @@ def test_Level1Design_inputs():
     ),
     model_serial_correlations=dict(mandatory=True,
     ),
+    orthogonalization=dict(mandatory=False,
+    ),
     session_info=dict(mandatory=True,
     ),
     )
diff --git a/nipype/interfaces/fsl/tests/test_auto_MCFLIRT.py b/nipype/interfaces/fsl/tests/test_auto_MCFLIRT.py
--- a/nipype/interfaces/fsl/tests/test_auto_MCFLIRT.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MCFLIRT.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MCFLIRT
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MELODIC.py b/nipype/interfaces/fsl/tests/test_auto_MELODIC.py
--- a/nipype/interfaces/fsl/tests/test_auto_MELODIC.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MELODIC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MELODIC
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MakeDyadicVectors.py b/nipype/interfaces/fsl/tests/test_auto_MakeDyadicVectors.py
--- a/nipype/interfaces/fsl/tests/test_auto_MakeDyadicVectors.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MakeDyadicVectors.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import MakeDyadicVectors
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MathsCommand.py b/nipype/interfaces/fsl/tests/test_auto_MathsCommand.py
--- a/nipype/interfaces/fsl/tests/test_auto_MathsCommand.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MathsCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import MathsCommand
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MaxImage.py b/nipype/interfaces/fsl/tests/test_auto_MaxImage.py
--- a/nipype/interfaces/fsl/tests/test_auto_MaxImage.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MaxImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import MaxImage
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MeanImage.py b/nipype/interfaces/fsl/tests/test_auto_MeanImage.py
--- a/nipype/interfaces/fsl/tests/test_auto_MeanImage.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MeanImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import MeanImage
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Merge.py b/nipype/interfaces/fsl/tests/test_auto_Merge.py
--- a/nipype/interfaces/fsl/tests/test_auto_Merge.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Merge.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Merge
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MotionOutliers.py b/nipype/interfaces/fsl/tests/test_auto_MotionOutliers.py
--- a/nipype/interfaces/fsl/tests/test_auto_MotionOutliers.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MotionOutliers.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import MotionOutliers
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MultiImageMaths.py b/nipype/interfaces/fsl/tests/test_auto_MultiImageMaths.py
--- a/nipype/interfaces/fsl/tests/test_auto_MultiImageMaths.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MultiImageMaths.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import MultiImageMaths
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_MultipleRegressDesign.py b/nipype/interfaces/fsl/tests/test_auto_MultipleRegressDesign.py
--- a/nipype/interfaces/fsl/tests/test_auto_MultipleRegressDesign.py
+++ b/nipype/interfaces/fsl/tests/test_auto_MultipleRegressDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MultipleRegressDesign
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Overlay.py b/nipype/interfaces/fsl/tests/test_auto_Overlay.py
--- a/nipype/interfaces/fsl/tests/test_auto_Overlay.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Overlay.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Overlay
 
 
@@ -8,7 +9,7 @@ def test_Overlay_inputs():
     auto_thresh_bg=dict(argstr='-a',
     mandatory=True,
     position=5,
-    xor=(u'auto_thresh_bg', u'full_bg_range', u'bg_thresh'),
+    xor=('auto_thresh_bg', 'full_bg_range', 'bg_thresh'),
     ),
     background_image=dict(argstr='%s',
     mandatory=True,
@@ -17,7 +18,7 @@ def test_Overlay_inputs():
     bg_thresh=dict(argstr='%.3f %.3f',
     mandatory=True,
     position=5,
-    xor=(u'auto_thresh_bg', u'full_bg_range', u'bg_thresh'),
+    xor=('auto_thresh_bg', 'full_bg_range', 'bg_thresh'),
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -25,7 +26,7 @@ def test_Overlay_inputs():
     full_bg_range=dict(argstr='-A',
     mandatory=True,
     position=5,
-    xor=(u'auto_thresh_bg', u'full_bg_range', u'bg_thresh'),
+    xor=('auto_thresh_bg', 'full_bg_range', 'bg_thresh'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -42,7 +43,7 @@ def test_Overlay_inputs():
     output_type=dict(),
     show_negative_stats=dict(argstr='%s',
     position=8,
-    xor=[u'stat_image2'],
+    xor=['stat_image2'],
     ),
     stat_image=dict(argstr='%s',
     mandatory=True,
@@ -50,7 +51,7 @@ def test_Overlay_inputs():
     ),
     stat_image2=dict(argstr='%s',
     position=9,
-    xor=[u'show_negative_stats'],
+    xor=['show_negative_stats'],
     ),
     stat_thresh=dict(argstr='%.2f %.2f',
     mandatory=True,
diff --git a/nipype/interfaces/fsl/tests/test_auto_PRELUDE.py b/nipype/interfaces/fsl/tests/test_auto_PRELUDE.py
--- a/nipype/interfaces/fsl/tests/test_auto_PRELUDE.py
+++ b/nipype/interfaces/fsl/tests/test_auto_PRELUDE.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import PRELUDE
 
 
@@ -7,7 +8,7 @@ def test_PRELUDE_inputs():
     ),
     complex_phase_file=dict(argstr='--complex=%s',
     mandatory=True,
-    xor=[u'magnitude_file', u'phase_file'],
+    xor=['magnitude_file', 'phase_file'],
     ),
     end=dict(argstr='--end=%d',
     ),
@@ -24,7 +25,7 @@ def test_PRELUDE_inputs():
     ),
     magnitude_file=dict(argstr='--abs=%s',
     mandatory=True,
-    xor=[u'complex_phase_file'],
+    xor=['complex_phase_file'],
     ),
     mask_file=dict(argstr='--mask=%s',
     ),
@@ -33,13 +34,13 @@ def test_PRELUDE_inputs():
     output_type=dict(),
     phase_file=dict(argstr='--phase=%s',
     mandatory=True,
-    xor=[u'complex_phase_file'],
+    xor=['complex_phase_file'],
     ),
     process2d=dict(argstr='--slices',
-    xor=[u'labelprocess2d'],
+    xor=['labelprocess2d'],
     ),
     process3d=dict(argstr='--force3D',
-    xor=[u'labelprocess2d', u'process2d'],
+    xor=['labelprocess2d', 'process2d'],
     ),
     rawphase_file=dict(argstr='--rawphase=%s',
     hash_files=False,
diff --git a/nipype/interfaces/fsl/tests/test_auto_PlotMotionParams.py b/nipype/interfaces/fsl/tests/test_auto_PlotMotionParams.py
--- a/nipype/interfaces/fsl/tests/test_auto_PlotMotionParams.py
+++ b/nipype/interfaces/fsl/tests/test_auto_PlotMotionParams.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import PlotMotionParams
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_PlotTimeSeries.py b/nipype/interfaces/fsl/tests/test_auto_PlotTimeSeries.py
--- a/nipype/interfaces/fsl/tests/test_auto_PlotTimeSeries.py
+++ b/nipype/interfaces/fsl/tests/test_auto_PlotTimeSeries.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import PlotTimeSeries
 
 
@@ -25,15 +26,15 @@ def test_PlotTimeSeries_inputs():
     ),
     output_type=dict(),
     plot_finish=dict(argstr='--finish=%d',
-    xor=(u'plot_range',),
+    xor=('plot_range',),
     ),
     plot_range=dict(argstr='%s',
-    xor=(u'plot_start', u'plot_finish'),
+    xor=('plot_start', 'plot_finish'),
     ),
     plot_size=dict(argstr='%s',
     ),
     plot_start=dict(argstr='--start=%d',
-    xor=(u'plot_range',),
+    xor=('plot_range',),
     ),
     sci_notation=dict(argstr='--sci',
     ),
@@ -47,13 +48,13 @@ def test_PlotTimeSeries_inputs():
     usedefault=True,
     ),
     y_max=dict(argstr='--ymax=%.2f',
-    xor=(u'y_range',),
+    xor=('y_range',),
     ),
     y_min=dict(argstr='--ymin=%.2f',
-    xor=(u'y_range',),
+    xor=('y_range',),
     ),
     y_range=dict(argstr='%s',
-    xor=(u'y_min', u'y_max'),
+    xor=('y_min', 'y_max'),
     ),
     )
     inputs = PlotTimeSeries.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_PowerSpectrum.py b/nipype/interfaces/fsl/tests/test_auto_PowerSpectrum.py
--- a/nipype/interfaces/fsl/tests/test_auto_PowerSpectrum.py
+++ b/nipype/interfaces/fsl/tests/test_auto_PowerSpectrum.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import PowerSpectrum
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_PrepareFieldmap.py b/nipype/interfaces/fsl/tests/test_auto_PrepareFieldmap.py
--- a/nipype/interfaces/fsl/tests/test_auto_PrepareFieldmap.py
+++ b/nipype/interfaces/fsl/tests/test_auto_PrepareFieldmap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import PrepareFieldmap
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ProbTrackX.py b/nipype/interfaces/fsl/tests/test_auto_ProbTrackX.py
--- a/nipype/interfaces/fsl/tests/test_auto_ProbTrackX.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ProbTrackX.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ProbTrackX
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_ProbTrackX2.py b/nipype/interfaces/fsl/tests/test_auto_ProbTrackX2.py
--- a/nipype/interfaces/fsl/tests/test_auto_ProbTrackX2.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ProbTrackX2.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ProbTrackX2
 
 
@@ -57,10 +58,10 @@ def test_ProbTrackX2_inputs():
     omatrix1=dict(argstr='--omatrix1',
     ),
     omatrix2=dict(argstr='--omatrix2',
-    requires=[u'target2'],
+    requires=['target2'],
     ),
     omatrix3=dict(argstr='--omatrix3',
-    requires=[u'target3', u'lrtarget3'],
+    requires=['target3', 'lrtarget3'],
     ),
     omatrix4=dict(argstr='--omatrix4',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_ProjThresh.py b/nipype/interfaces/fsl/tests/test_auto_ProjThresh.py
--- a/nipype/interfaces/fsl/tests/test_auto_ProjThresh.py
+++ b/nipype/interfaces/fsl/tests/test_auto_ProjThresh.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import ProjThresh
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Randomise.py b/nipype/interfaces/fsl/tests/test_auto_Randomise.py
--- a/nipype/interfaces/fsl/tests/test_auto_Randomise.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Randomise.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Randomise
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Reorient2Std.py b/nipype/interfaces/fsl/tests/test_auto_Reorient2Std.py
--- a/nipype/interfaces/fsl/tests/test_auto_Reorient2Std.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Reorient2Std.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Reorient2Std
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_RobustFOV.py b/nipype/interfaces/fsl/tests/test_auto_RobustFOV.py
--- a/nipype/interfaces/fsl/tests/test_auto_RobustFOV.py
+++ b/nipype/interfaces/fsl/tests/test_auto_RobustFOV.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import RobustFOV
 
 
@@ -17,7 +18,7 @@ def test_RobustFOV_inputs():
     ),
     out_roi=dict(argstr='-r %s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_ROI',
     ),
     output_type=dict(),
diff --git a/nipype/interfaces/fsl/tests/test_auto_SMM.py b/nipype/interfaces/fsl/tests/test_auto_SMM.py
--- a/nipype/interfaces/fsl/tests/test_auto_SMM.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SMM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import SMM
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_SUSAN.py b/nipype/interfaces/fsl/tests/test_auto_SUSAN.py
--- a/nipype/interfaces/fsl/tests/test_auto_SUSAN.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SUSAN.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SUSAN
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_SigLoss.py b/nipype/interfaces/fsl/tests/test_auto_SigLoss.py
--- a/nipype/interfaces/fsl/tests/test_auto_SigLoss.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SigLoss.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SigLoss
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_SliceTimer.py b/nipype/interfaces/fsl/tests/test_auto_SliceTimer.py
--- a/nipype/interfaces/fsl/tests/test_auto_SliceTimer.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SliceTimer.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SliceTimer
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Slicer.py b/nipype/interfaces/fsl/tests/test_auto_Slicer.py
--- a/nipype/interfaces/fsl/tests/test_auto_Slicer.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Slicer.py
@@ -1,12 +1,13 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Slicer
 
 
 def test_Slicer_inputs():
     input_map = dict(all_axial=dict(argstr='-A',
     position=10,
-    requires=[u'image_width'],
-    xor=(u'single_slice', u'middle_slices', u'all_axial', u'sample_axial'),
+    requires=['image_width'],
+    xor=('single_slice', 'middle_slices', 'all_axial', 'sample_axial'),
     ),
     args=dict(argstr='%s',
     ),
@@ -41,7 +42,7 @@ def test_Slicer_inputs():
     ),
     middle_slices=dict(argstr='-a',
     position=10,
-    xor=(u'single_slice', u'middle_slices', u'all_axial', u'sample_axial'),
+    xor=('single_slice', 'middle_slices', 'all_axial', 'sample_axial'),
     ),
     nearest_neighbour=dict(argstr='-n',
     position=8,
@@ -54,8 +55,8 @@ def test_Slicer_inputs():
     output_type=dict(),
     sample_axial=dict(argstr='-S %d',
     position=10,
-    requires=[u'image_width'],
-    xor=(u'single_slice', u'middle_slices', u'all_axial', u'sample_axial'),
+    requires=['image_width'],
+    xor=('single_slice', 'middle_slices', 'all_axial', 'sample_axial'),
     ),
     scaling=dict(argstr='-s %f',
     position=0,
@@ -66,8 +67,8 @@ def test_Slicer_inputs():
     ),
     single_slice=dict(argstr='-%s',
     position=10,
-    requires=[u'slice_number'],
-    xor=(u'single_slice', u'middle_slices', u'all_axial', u'sample_axial'),
+    requires=['slice_number'],
+    xor=('single_slice', 'middle_slices', 'all_axial', 'sample_axial'),
     ),
     slice_number=dict(argstr='-%d',
     position=11,
diff --git a/nipype/interfaces/fsl/tests/test_auto_Smooth.py b/nipype/interfaces/fsl/tests/test_auto_Smooth.py
--- a/nipype/interfaces/fsl/tests/test_auto_Smooth.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Smooth.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Smooth
 
 
@@ -11,7 +12,7 @@ def test_Smooth_inputs():
     fwhm=dict(argstr='-kernel gauss %.03f -fmean',
     mandatory=True,
     position=1,
-    xor=[u'sigma'],
+    xor=['sigma'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -24,11 +25,11 @@ def test_Smooth_inputs():
     sigma=dict(argstr='-kernel gauss %.03f -fmean',
     mandatory=True,
     position=1,
-    xor=[u'fwhm'],
+    xor=['fwhm'],
     ),
     smoothed_file=dict(argstr='%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_smooth',
     position=2,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_SmoothEstimate.py b/nipype/interfaces/fsl/tests/test_auto_SmoothEstimate.py
--- a/nipype/interfaces/fsl/tests/test_auto_SmoothEstimate.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SmoothEstimate.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import SmoothEstimate
 
 
@@ -7,7 +8,7 @@ def test_SmoothEstimate_inputs():
     ),
     dof=dict(argstr='--dof=%d',
     mandatory=True,
-    xor=[u'zstat_file'],
+    xor=['zstat_file'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -20,12 +21,12 @@ def test_SmoothEstimate_inputs():
     ),
     output_type=dict(),
     residual_fit_file=dict(argstr='--res=%s',
-    requires=[u'dof'],
+    requires=['dof'],
     ),
     terminal_output=dict(nohash=True,
     ),
     zstat_file=dict(argstr='--zstat=%s',
-    xor=[u'dof'],
+    xor=['dof'],
     ),
     )
     inputs = SmoothEstimate.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_SpatialFilter.py b/nipype/interfaces/fsl/tests/test_auto_SpatialFilter.py
--- a/nipype/interfaces/fsl/tests/test_auto_SpatialFilter.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SpatialFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import SpatialFilter
 
 
@@ -20,14 +21,14 @@ def test_SpatialFilter_inputs():
     ),
     kernel_file=dict(argstr='%s',
     position=5,
-    xor=[u'kernel_size'],
+    xor=['kernel_size'],
     ),
     kernel_shape=dict(argstr='-kernel %s',
     position=4,
     ),
     kernel_size=dict(argstr='%.4f',
     position=5,
-    xor=[u'kernel_file'],
+    xor=['kernel_file'],
     ),
     nan2zeros=dict(argstr='-nan',
     position=3,
diff --git a/nipype/interfaces/fsl/tests/test_auto_Split.py b/nipype/interfaces/fsl/tests/test_auto_Split.py
--- a/nipype/interfaces/fsl/tests/test_auto_Split.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Split.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Split
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_StdImage.py b/nipype/interfaces/fsl/tests/test_auto_StdImage.py
--- a/nipype/interfaces/fsl/tests/test_auto_StdImage.py
+++ b/nipype/interfaces/fsl/tests/test_auto_StdImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import StdImage
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_SwapDimensions.py b/nipype/interfaces/fsl/tests/test_auto_SwapDimensions.py
--- a/nipype/interfaces/fsl/tests/test_auto_SwapDimensions.py
+++ b/nipype/interfaces/fsl/tests/test_auto_SwapDimensions.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import SwapDimensions
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_TOPUP.py b/nipype/interfaces/fsl/tests/test_auto_TOPUP.py
--- a/nipype/interfaces/fsl/tests/test_auto_TOPUP.py
+++ b/nipype/interfaces/fsl/tests/test_auto_TOPUP.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..epi import TOPUP
 
 
@@ -10,12 +11,12 @@ def test_TOPUP_inputs():
     ),
     encoding_direction=dict(argstr='--datain=%s',
     mandatory=True,
-    requires=[u'readout_times'],
-    xor=[u'encoding_file'],
+    requires=['readout_times'],
+    xor=['encoding_file'],
     ),
     encoding_file=dict(argstr='--datain=%s',
     mandatory=True,
-    xor=[u'encoding_direction'],
+    xor=['encoding_direction'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -40,29 +41,29 @@ def test_TOPUP_inputs():
     ),
     out_base=dict(argstr='--out=%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_base',
     ),
     out_corrected=dict(argstr='--iout=%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_corrected',
     ),
     out_field=dict(argstr='--fout=%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_field',
     ),
     out_logfile=dict(argstr='--logout=%s',
     hash_files=False,
     keep_extension=True,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_topup.log',
     ),
     output_type=dict(),
     readout_times=dict(mandatory=True,
-    requires=[u'encoding_direction'],
-    xor=[u'encoding_file'],
+    requires=['encoding_direction'],
+    xor=['encoding_file'],
     ),
     reg_lambda=dict(argstr='--miter=%0.f',
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_TemporalFilter.py b/nipype/interfaces/fsl/tests/test_auto_TemporalFilter.py
--- a/nipype/interfaces/fsl/tests/test_auto_TemporalFilter.py
+++ b/nipype/interfaces/fsl/tests/test_auto_TemporalFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import TemporalFilter
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_Threshold.py b/nipype/interfaces/fsl/tests/test_auto_Threshold.py
--- a/nipype/interfaces/fsl/tests/test_auto_Threshold.py
+++ b/nipype/interfaces/fsl/tests/test_auto_Threshold.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import Threshold
 
 
@@ -38,7 +39,7 @@ def test_Threshold_inputs():
     mandatory=True,
     position=4,
     ),
-    use_nonzero_voxels=dict(requires=[u'use_robust_range'],
+    use_nonzero_voxels=dict(requires=['use_robust_range'],
     ),
     use_robust_range=dict(),
     )
diff --git a/nipype/interfaces/fsl/tests/test_auto_TractSkeleton.py b/nipype/interfaces/fsl/tests/test_auto_TractSkeleton.py
--- a/nipype/interfaces/fsl/tests/test_auto_TractSkeleton.py
+++ b/nipype/interfaces/fsl/tests/test_auto_TractSkeleton.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import TractSkeleton
 
 
@@ -22,10 +23,10 @@ def test_TractSkeleton_inputs():
     ),
     output_type=dict(),
     project_data=dict(argstr='-p %.3f %s %s %s %s',
-    requires=[u'threshold', u'distance_map', u'data_file'],
+    requires=['threshold', 'distance_map', 'data_file'],
     ),
     projected_data=dict(),
-    search_mask_file=dict(xor=[u'use_cingulum_mask'],
+    search_mask_file=dict(xor=['use_cingulum_mask'],
     ),
     skeleton_file=dict(argstr='-o %s',
     ),
@@ -33,7 +34,7 @@ def test_TractSkeleton_inputs():
     ),
     threshold=dict(),
     use_cingulum_mask=dict(usedefault=True,
-    xor=[u'search_mask_file'],
+    xor=['search_mask_file'],
     ),
     )
     inputs = TractSkeleton.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_UnaryMaths.py b/nipype/interfaces/fsl/tests/test_auto_UnaryMaths.py
--- a/nipype/interfaces/fsl/tests/test_auto_UnaryMaths.py
+++ b/nipype/interfaces/fsl/tests/test_auto_UnaryMaths.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maths import UnaryMaths
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_VecReg.py b/nipype/interfaces/fsl/tests/test_auto_VecReg.py
--- a/nipype/interfaces/fsl/tests/test_auto_VecReg.py
+++ b/nipype/interfaces/fsl/tests/test_auto_VecReg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import VecReg
 
 
diff --git a/nipype/interfaces/fsl/tests/test_auto_WarpPoints.py b/nipype/interfaces/fsl/tests/test_auto_WarpPoints.py
--- a/nipype/interfaces/fsl/tests/test_auto_WarpPoints.py
+++ b/nipype/interfaces/fsl/tests/test_auto_WarpPoints.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import WarpPoints
 
 
@@ -6,10 +7,10 @@ def test_WarpPoints_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
     coord_mm=dict(argstr='-mm',
-    xor=[u'coord_vox'],
+    xor=['coord_vox'],
     ),
     coord_vox=dict(argstr='-vox',
-    xor=[u'coord_mm'],
+    xor=['coord_mm'],
     ),
     dest_file=dict(argstr='-dest %s',
     mandatory=True,
@@ -34,10 +35,10 @@ def test_WarpPoints_inputs():
     terminal_output=dict(nohash=True,
     ),
     warp_file=dict(argstr='-warp %s',
-    xor=[u'xfm_file'],
+    xor=['xfm_file'],
     ),
     xfm_file=dict(argstr='-xfm %s',
-    xor=[u'warp_file'],
+    xor=['warp_file'],
     ),
     )
     inputs = WarpPoints.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_WarpPointsToStd.py b/nipype/interfaces/fsl/tests/test_auto_WarpPointsToStd.py
--- a/nipype/interfaces/fsl/tests/test_auto_WarpPointsToStd.py
+++ b/nipype/interfaces/fsl/tests/test_auto_WarpPointsToStd.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import WarpPointsToStd
 
 
@@ -6,10 +7,10 @@ def test_WarpPointsToStd_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
     coord_mm=dict(argstr='-mm',
-    xor=[u'coord_vox'],
+    xor=['coord_vox'],
     ),
     coord_vox=dict(argstr='-vox',
-    xor=[u'coord_mm'],
+    xor=['coord_mm'],
     ),
     environ=dict(nohash=True,
     usedefault=True,
@@ -36,10 +37,10 @@ def test_WarpPointsToStd_inputs():
     terminal_output=dict(nohash=True,
     ),
     warp_file=dict(argstr='-warp %s',
-    xor=[u'xfm_file'],
+    xor=['xfm_file'],
     ),
     xfm_file=dict(argstr='-xfm %s',
-    xor=[u'warp_file'],
+    xor=['warp_file'],
     ),
     )
     inputs = WarpPointsToStd.input_spec()
diff --git a/nipype/interfaces/fsl/tests/test_auto_WarpUtils.py b/nipype/interfaces/fsl/tests/test_auto_WarpUtils.py
--- a/nipype/interfaces/fsl/tests/test_auto_WarpUtils.py
+++ b/nipype/interfaces/fsl/tests/test_auto_WarpUtils.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import WarpUtils
 
 
@@ -17,7 +18,7 @@ def test_WarpUtils_inputs():
     knot_space=dict(argstr='--knotspace=%d,%d,%d',
     ),
     out_file=dict(argstr='--out=%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     output_name='out_file',
     position=-1,
     ),
diff --git a/nipype/interfaces/fsl/tests/test_auto_XFibres5.py b/nipype/interfaces/fsl/tests/test_auto_XFibres5.py
--- a/nipype/interfaces/fsl/tests/test_auto_XFibres5.py
+++ b/nipype/interfaces/fsl/tests/test_auto_XFibres5.py
@@ -1,10 +1,11 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dti import XFibres5
 
 
 def test_XFibres5_inputs():
     input_map = dict(all_ard=dict(argstr='--allard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     args=dict(argstr='%s',
     ),
@@ -19,7 +20,7 @@ def test_XFibres5_inputs():
     mandatory=True,
     ),
     cnlinear=dict(argstr='--cnonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     dwi=dict(argstr='--data=%s',
     mandatory=True,
@@ -28,10 +29,10 @@ def test_XFibres5_inputs():
     usedefault=True,
     ),
     f0_ard=dict(argstr='--f0 --ardf0',
-    xor=[u'f0_noard', u'f0_ard', u'all_ard'],
+    xor=['f0_noard', 'f0_ard', 'all_ard'],
     ),
     f0_noard=dict(argstr='--f0',
-    xor=[u'f0_noard', u'f0_ard'],
+    xor=['f0_noard', 'f0_ard'],
     ),
     force_dir=dict(argstr='--forcedir',
     usedefault=True,
@@ -58,13 +59,13 @@ def test_XFibres5_inputs():
     n_jumps=dict(argstr='--njumps=%d',
     ),
     no_ard=dict(argstr='--noard',
-    xor=(u'no_ard', u'all_ard'),
+    xor=('no_ard', 'all_ard'),
     ),
     no_spat=dict(argstr='--nospat',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     non_linear=dict(argstr='--nonlinear',
-    xor=(u'no_spat', u'non_linear', u'cnlinear'),
+    xor=('no_spat', 'non_linear', 'cnlinear'),
     ),
     output_type=dict(),
     rician=dict(argstr='--rician',
diff --git a/nipype/interfaces/minc/tests/test_auto_Average.py b/nipype/interfaces/minc/tests/test_auto_Average.py
--- a/nipype/interfaces/minc/tests/test_auto_Average.py
+++ b/nipype/interfaces/minc/tests/test_auto_Average.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Average
 
 
@@ -14,13 +15,13 @@ def test_Average_inputs():
     binvalue=dict(argstr='-binvalue %s',
     ),
     check_dimensions=dict(argstr='-check_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     clobber=dict(argstr='-clobber',
     usedefault=True,
     ),
     copy_header=dict(argstr='-copy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     debug=dict(argstr='-debug',
     ),
@@ -29,34 +30,34 @@ def test_Average_inputs():
     ),
     filelist=dict(argstr='-filelist %s',
     mandatory=True,
-    xor=(u'input_files', u'filelist'),
+    xor=('input_files', 'filelist'),
     ),
     format_byte=dict(argstr='-byte',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_double=dict(argstr='-double',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_filetype=dict(argstr='-filetype',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_float=dict(argstr='-float',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_int=dict(argstr='-int',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_long=dict(argstr='-long',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_short=dict(argstr='-short',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_signed=dict(argstr='-signed',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_unsigned=dict(argstr='-unsigned',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -65,31 +66,31 @@ def test_Average_inputs():
     mandatory=True,
     position=-2,
     sep=' ',
-    xor=(u'input_files', u'filelist'),
+    xor=('input_files', 'filelist'),
     ),
     max_buffer_size_in_kb=dict(argstr='-max_buffer_size_in_kb %d',
     ),
     no_check_dimensions=dict(argstr='-nocheck_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     no_copy_header=dict(argstr='-nocopy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     nonormalize=dict(argstr='-nonormalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     normalize=dict(argstr='-normalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_averaged.mnc',
     position=-1,
     ),
     quiet=dict(argstr='-quiet',
-    xor=(u'verbose', u'quiet'),
+    xor=('verbose', 'quiet'),
     ),
     sdfile=dict(argstr='-sdfile %s',
     ),
@@ -98,7 +99,7 @@ def test_Average_inputs():
     two=dict(argstr='-2',
     ),
     verbose=dict(argstr='-verbose',
-    xor=(u'verbose', u'quiet'),
+    xor=('verbose', 'quiet'),
     ),
     voxel_range=dict(argstr='-range %d %d',
     ),
@@ -106,7 +107,7 @@ def test_Average_inputs():
     sep=',',
     ),
     width_weighted=dict(argstr='-width_weighted',
-    requires=(u'avgdim',),
+    requires=('avgdim',),
     ),
     )
     inputs = Average.input_spec()
diff --git a/nipype/interfaces/minc/tests/test_auto_BBox.py b/nipype/interfaces/minc/tests/test_auto_BBox.py
--- a/nipype/interfaces/minc/tests/test_auto_BBox.py
+++ b/nipype/interfaces/minc/tests/test_auto_BBox.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import BBox
 
 
@@ -22,7 +23,7 @@ def test_BBox_inputs():
     position=-2,
     ),
     one_line=dict(argstr='-one_line',
-    xor=(u'one_line', u'two_lines'),
+    xor=('one_line', 'two_lines'),
     ),
     out_file=dict(argstr='> %s',
     genfile=True,
@@ -30,7 +31,7 @@ def test_BBox_inputs():
     ),
     output_file=dict(hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_bbox.txt',
     position=-1,
     ),
@@ -39,7 +40,7 @@ def test_BBox_inputs():
     threshold=dict(argstr='-threshold',
     ),
     two_lines=dict(argstr='-two_lines',
-    xor=(u'one_line', u'two_lines'),
+    xor=('one_line', 'two_lines'),
     ),
     )
     inputs = BBox.input_spec()
diff --git a/nipype/interfaces/minc/tests/test_auto_Beast.py b/nipype/interfaces/minc/tests/test_auto_Beast.py
--- a/nipype/interfaces/minc/tests/test_auto_Beast.py
+++ b/nipype/interfaces/minc/tests/test_auto_Beast.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Beast
 
 
@@ -43,7 +44,7 @@ def test_Beast_inputs():
     ),
     output_file=dict(argstr='%s',
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_beast_mask.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_BestLinReg.py b/nipype/interfaces/minc/tests/test_auto_BestLinReg.py
--- a/nipype/interfaces/minc/tests/test_auto_BestLinReg.py
+++ b/nipype/interfaces/minc/tests/test_auto_BestLinReg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import BestLinReg
 
 
@@ -18,7 +19,7 @@ def test_BestLinReg_inputs():
     genfile=True,
     hash_files=False,
     keep_extension=False,
-    name_source=[u'source'],
+    name_source=['source'],
     name_template='%s_bestlinreg.mnc',
     position=-1,
     ),
@@ -26,7 +27,7 @@ def test_BestLinReg_inputs():
     genfile=True,
     hash_files=False,
     keep_extension=False,
-    name_source=[u'source'],
+    name_source=['source'],
     name_template='%s_bestlinreg.xfm',
     position=-2,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_BigAverage.py b/nipype/interfaces/minc/tests/test_auto_BigAverage.py
--- a/nipype/interfaces/minc/tests/test_auto_BigAverage.py
+++ b/nipype/interfaces/minc/tests/test_auto_BigAverage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import BigAverage
 
 
@@ -22,7 +23,7 @@ def test_BigAverage_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_bigaverage.mnc',
     position=-1,
     ),
@@ -32,7 +33,7 @@ def test_BigAverage_inputs():
     ),
     sd_file=dict(argstr='--sdfile %s',
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_bigaverage_stdev.mnc',
     ),
     terminal_output=dict(nohash=True,
diff --git a/nipype/interfaces/minc/tests/test_auto_Blob.py b/nipype/interfaces/minc/tests/test_auto_Blob.py
--- a/nipype/interfaces/minc/tests/test_auto_Blob.py
+++ b/nipype/interfaces/minc/tests/test_auto_Blob.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Blob
 
 
@@ -22,7 +23,7 @@ def test_Blob_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_blob.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Blur.py b/nipype/interfaces/minc/tests/test_auto_Blur.py
--- a/nipype/interfaces/minc/tests/test_auto_Blur.py
+++ b/nipype/interfaces/minc/tests/test_auto_Blur.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Blur
 
 
@@ -15,14 +16,14 @@ def test_Blur_inputs():
     ),
     fwhm=dict(argstr='-fwhm %s',
     mandatory=True,
-    xor=(u'fwhm', u'fwhm3d', u'standard_dev'),
+    xor=('fwhm', 'fwhm3d', 'standard_dev'),
     ),
     fwhm3d=dict(argstr='-3dfwhm %s %s %s',
     mandatory=True,
-    xor=(u'fwhm', u'fwhm3d', u'standard_dev'),
+    xor=('fwhm', 'fwhm3d', 'standard_dev'),
     ),
     gaussian=dict(argstr='-gaussian',
-    xor=(u'gaussian', u'rect'),
+    xor=('gaussian', 'rect'),
     ),
     gradient=dict(argstr='-gradient',
     ),
@@ -41,11 +42,11 @@ def test_Blur_inputs():
     partial=dict(argstr='-partial',
     ),
     rect=dict(argstr='-rect',
-    xor=(u'gaussian', u'rect'),
+    xor=('gaussian', 'rect'),
     ),
     standard_dev=dict(argstr='-standarddev %s',
     mandatory=True,
-    xor=(u'fwhm', u'fwhm3d', u'standard_dev'),
+    xor=('fwhm', 'fwhm3d', 'standard_dev'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Calc.py b/nipype/interfaces/minc/tests/test_auto_Calc.py
--- a/nipype/interfaces/minc/tests/test_auto_Calc.py
+++ b/nipype/interfaces/minc/tests/test_auto_Calc.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Calc
 
 
@@ -6,13 +7,13 @@ def test_Calc_inputs():
     input_map = dict(args=dict(argstr='%s',
     ),
     check_dimensions=dict(argstr='-check_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     clobber=dict(argstr='-clobber',
     usedefault=True,
     ),
     copy_header=dict(argstr='-copy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     debug=dict(argstr='-debug',
     ),
@@ -24,42 +25,42 @@ def test_Calc_inputs():
     ),
     expfile=dict(argstr='-expfile %s',
     mandatory=True,
-    xor=(u'expression', u'expfile'),
+    xor=('expression', 'expfile'),
     ),
     expression=dict(argstr="-expression '%s'",
     mandatory=True,
-    xor=(u'expression', u'expfile'),
+    xor=('expression', 'expfile'),
     ),
     filelist=dict(argstr='-filelist %s',
     mandatory=True,
-    xor=(u'input_files', u'filelist'),
+    xor=('input_files', 'filelist'),
     ),
     format_byte=dict(argstr='-byte',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_double=dict(argstr='-double',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_filetype=dict(argstr='-filetype',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_float=dict(argstr='-float',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_int=dict(argstr='-int',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_long=dict(argstr='-long',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_short=dict(argstr='-short',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_signed=dict(argstr='-signed',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_unsigned=dict(argstr='-unsigned',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -75,39 +76,39 @@ def test_Calc_inputs():
     usedefault=False,
     ),
     no_check_dimensions=dict(argstr='-nocheck_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     no_copy_header=dict(argstr='-nocopy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     outfiles=dict(),
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_calc.mnc',
     position=-1,
     ),
     output_illegal=dict(argstr='-illegal_value',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     output_nan=dict(argstr='-nan',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     output_zero=dict(argstr='-zero',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     propagate_nan=dict(argstr='-propagate_nan',
     ),
     quiet=dict(argstr='-quiet',
-    xor=(u'verbose', u'quiet'),
+    xor=('verbose', 'quiet'),
     ),
     terminal_output=dict(nohash=True,
     ),
     two=dict(argstr='-2',
     ),
     verbose=dict(argstr='-verbose',
-    xor=(u'verbose', u'quiet'),
+    xor=('verbose', 'quiet'),
     ),
     voxel_range=dict(argstr='-range %d %d',
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Convert.py b/nipype/interfaces/minc/tests/test_auto_Convert.py
--- a/nipype/interfaces/minc/tests/test_auto_Convert.py
+++ b/nipype/interfaces/minc/tests/test_auto_Convert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Convert
 
 
@@ -26,7 +27,7 @@ def test_Convert_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_convert_output.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Copy.py b/nipype/interfaces/minc/tests/test_auto_Copy.py
--- a/nipype/interfaces/minc/tests/test_auto_Copy.py
+++ b/nipype/interfaces/minc/tests/test_auto_Copy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Copy
 
 
@@ -18,15 +19,15 @@ def test_Copy_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_copy.mnc',
     position=-1,
     ),
     pixel_values=dict(argstr='-pixel_values',
-    xor=(u'pixel_values', u'real_values'),
+    xor=('pixel_values', 'real_values'),
     ),
     real_values=dict(argstr='-real_values',
-    xor=(u'pixel_values', u'real_values'),
+    xor=('pixel_values', 'real_values'),
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Dump.py b/nipype/interfaces/minc/tests/test_auto_Dump.py
--- a/nipype/interfaces/minc/tests/test_auto_Dump.py
+++ b/nipype/interfaces/minc/tests/test_auto_Dump.py
@@ -1,24 +1,25 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Dump
 
 
 def test_Dump_inputs():
     input_map = dict(annotations_brief=dict(argstr='-b %s',
-    xor=(u'annotations_brief', u'annotations_full'),
+    xor=('annotations_brief', 'annotations_full'),
     ),
     annotations_full=dict(argstr='-f %s',
-    xor=(u'annotations_brief', u'annotations_full'),
+    xor=('annotations_brief', 'annotations_full'),
     ),
     args=dict(argstr='%s',
     ),
     coordinate_data=dict(argstr='-c',
-    xor=(u'coordinate_data', u'header_data'),
+    xor=('coordinate_data', 'header_data'),
     ),
     environ=dict(nohash=True,
     usedefault=True,
     ),
     header_data=dict(argstr='-h',
-    xor=(u'coordinate_data', u'header_data'),
+    xor=('coordinate_data', 'header_data'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -38,7 +39,7 @@ def test_Dump_inputs():
     ),
     output_file=dict(hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_dump.txt',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Extract.py b/nipype/interfaces/minc/tests/test_auto_Extract.py
--- a/nipype/interfaces/minc/tests/test_auto_Extract.py
+++ b/nipype/interfaces/minc/tests/test_auto_Extract.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Extract
 
 
@@ -12,40 +13,40 @@ def test_Extract_inputs():
     usedefault=True,
     ),
     flip_any_direction=dict(argstr='-any_direction',
-    xor=(u'flip_positive_direction', u'flip_negative_direction', u'flip_any_direction'),
+    xor=('flip_positive_direction', 'flip_negative_direction', 'flip_any_direction'),
     ),
     flip_negative_direction=dict(argstr='-negative_direction',
-    xor=(u'flip_positive_direction', u'flip_negative_direction', u'flip_any_direction'),
+    xor=('flip_positive_direction', 'flip_negative_direction', 'flip_any_direction'),
     ),
     flip_positive_direction=dict(argstr='-positive_direction',
-    xor=(u'flip_positive_direction', u'flip_negative_direction', u'flip_any_direction'),
+    xor=('flip_positive_direction', 'flip_negative_direction', 'flip_any_direction'),
     ),
     flip_x_any=dict(argstr='-xanydirection',
-    xor=(u'flip_x_positive', u'flip_x_negative', u'flip_x_any'),
+    xor=('flip_x_positive', 'flip_x_negative', 'flip_x_any'),
     ),
     flip_x_negative=dict(argstr='-xdirection',
-    xor=(u'flip_x_positive', u'flip_x_negative', u'flip_x_any'),
+    xor=('flip_x_positive', 'flip_x_negative', 'flip_x_any'),
     ),
     flip_x_positive=dict(argstr='+xdirection',
-    xor=(u'flip_x_positive', u'flip_x_negative', u'flip_x_any'),
+    xor=('flip_x_positive', 'flip_x_negative', 'flip_x_any'),
     ),
     flip_y_any=dict(argstr='-yanydirection',
-    xor=(u'flip_y_positive', u'flip_y_negative', u'flip_y_any'),
+    xor=('flip_y_positive', 'flip_y_negative', 'flip_y_any'),
     ),
     flip_y_negative=dict(argstr='-ydirection',
-    xor=(u'flip_y_positive', u'flip_y_negative', u'flip_y_any'),
+    xor=('flip_y_positive', 'flip_y_negative', 'flip_y_any'),
     ),
     flip_y_positive=dict(argstr='+ydirection',
-    xor=(u'flip_y_positive', u'flip_y_negative', u'flip_y_any'),
+    xor=('flip_y_positive', 'flip_y_negative', 'flip_y_any'),
     ),
     flip_z_any=dict(argstr='-zanydirection',
-    xor=(u'flip_z_positive', u'flip_z_negative', u'flip_z_any'),
+    xor=('flip_z_positive', 'flip_z_negative', 'flip_z_any'),
     ),
     flip_z_negative=dict(argstr='-zdirection',
-    xor=(u'flip_z_positive', u'flip_z_negative', u'flip_z_any'),
+    xor=('flip_z_positive', 'flip_z_negative', 'flip_z_any'),
     ),
     flip_z_positive=dict(argstr='+zdirection',
-    xor=(u'flip_z_positive', u'flip_z_negative', u'flip_z_any'),
+    xor=('flip_z_positive', 'flip_z_negative', 'flip_z_any'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -61,10 +62,10 @@ def test_Extract_inputs():
     position=-2,
     ),
     nonormalize=dict(argstr='-nonormalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     normalize=dict(argstr='-normalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     out_file=dict(argstr='> %s',
     genfile=True,
@@ -72,7 +73,7 @@ def test_Extract_inputs():
     ),
     output_file=dict(hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s.raw',
     position=-1,
     ),
@@ -82,33 +83,33 @@ def test_Extract_inputs():
     terminal_output=dict(nohash=True,
     ),
     write_ascii=dict(argstr='-ascii',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_byte=dict(argstr='-byte',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_double=dict(argstr='-double',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_float=dict(argstr='-float',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_int=dict(argstr='-int',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_long=dict(argstr='-long',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_range=dict(argstr='-range %s %s',
     ),
     write_short=dict(argstr='-short',
-    xor=(u'write_ascii', u'write_ascii', u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double', u'write_signed', u'write_unsigned'),
+    xor=('write_ascii', 'write_ascii', 'write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double', 'write_signed', 'write_unsigned'),
     ),
     write_signed=dict(argstr='-signed',
-    xor=(u'write_signed', u'write_unsigned'),
+    xor=('write_signed', 'write_unsigned'),
     ),
     write_unsigned=dict(argstr='-unsigned',
-    xor=(u'write_signed', u'write_unsigned'),
+    xor=('write_signed', 'write_unsigned'),
     ),
     )
     inputs = Extract.input_spec()
diff --git a/nipype/interfaces/minc/tests/test_auto_Gennlxfm.py b/nipype/interfaces/minc/tests/test_auto_Gennlxfm.py
--- a/nipype/interfaces/minc/tests/test_auto_Gennlxfm.py
+++ b/nipype/interfaces/minc/tests/test_auto_Gennlxfm.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Gennlxfm
 
 
@@ -21,7 +22,7 @@ def test_Gennlxfm_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'like'],
+    name_source=['like'],
     name_template='%s_gennlxfm.xfm',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Math.py b/nipype/interfaces/minc/tests/test_auto_Math.py
--- a/nipype/interfaces/minc/tests/test_auto_Math.py
+++ b/nipype/interfaces/minc/tests/test_auto_Math.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Math
 
 
@@ -22,7 +23,7 @@ def test_Math_inputs():
     calc_sub=dict(argstr='-sub',
     ),
     check_dimensions=dict(argstr='-check_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     clamp=dict(argstr='-clamp -const2 %s %s',
     ),
@@ -30,7 +31,7 @@ def test_Math_inputs():
     usedefault=True,
     ),
     copy_header=dict(argstr='-copy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     count_valid=dict(argstr='-count_valid',
     ),
@@ -43,34 +44,34 @@ def test_Math_inputs():
     ),
     filelist=dict(argstr='-filelist %s',
     mandatory=True,
-    xor=(u'input_files', u'filelist'),
+    xor=('input_files', 'filelist'),
     ),
     format_byte=dict(argstr='-byte',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_double=dict(argstr='-double',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_filetype=dict(argstr='-filetype',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_float=dict(argstr='-float',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_int=dict(argstr='-int',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_long=dict(argstr='-long',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_short=dict(argstr='-short',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_signed=dict(argstr='-signed',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_unsigned=dict(argstr='-unsigned',
-    xor=(u'format_filetype', u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_filetype', 'format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -81,7 +82,7 @@ def test_Math_inputs():
     mandatory=True,
     position=-2,
     sep=' ',
-    xor=(u'input_files', u'filelist'),
+    xor=('input_files', 'filelist'),
     ),
     invert=dict(argstr='-invert -const %s',
     ),
@@ -98,28 +99,28 @@ def test_Math_inputs():
     nisnan=dict(argstr='-nisnan',
     ),
     no_check_dimensions=dict(argstr='-nocheck_dimensions',
-    xor=(u'check_dimensions', u'no_check_dimensions'),
+    xor=('check_dimensions', 'no_check_dimensions'),
     ),
     no_copy_header=dict(argstr='-nocopy_header',
-    xor=(u'copy_header', u'no_copy_header'),
+    xor=('copy_header', 'no_copy_header'),
     ),
     nsegment=dict(argstr='-nsegment -const2 %s %s',
     ),
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_mincmath.mnc',
     position=-1,
     ),
     output_illegal=dict(argstr='-illegal_value',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     output_nan=dict(argstr='-nan',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     output_zero=dict(argstr='-zero',
-    xor=(u'output_nan', u'output_zero', u'output_illegal_value'),
+    xor=('output_nan', 'output_zero', 'output_illegal_value'),
     ),
     percentdiff=dict(argstr='-percentdiff',
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_NlpFit.py b/nipype/interfaces/minc/tests/test_auto_NlpFit.py
--- a/nipype/interfaces/minc/tests/test_auto_NlpFit.py
+++ b/nipype/interfaces/minc/tests/test_auto_NlpFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import NlpFit
 
 
diff --git a/nipype/interfaces/minc/tests/test_auto_Norm.py b/nipype/interfaces/minc/tests/test_auto_Norm.py
--- a/nipype/interfaces/minc/tests/test_auto_Norm.py
+++ b/nipype/interfaces/minc/tests/test_auto_Norm.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Norm
 
 
@@ -34,13 +35,13 @@ def test_Norm_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_norm.mnc',
     position=-1,
     ),
     output_threshold_mask=dict(argstr='-threshold_mask %s',
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_norm_threshold_mask.mnc',
     ),
     terminal_output=dict(nohash=True,
diff --git a/nipype/interfaces/minc/tests/test_auto_Pik.py b/nipype/interfaces/minc/tests/test_auto_Pik.py
--- a/nipype/interfaces/minc/tests/test_auto_Pik.py
+++ b/nipype/interfaces/minc/tests/test_auto_Pik.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Pik
 
 
@@ -8,7 +9,7 @@ def test_Pik_inputs():
     args=dict(argstr='%s',
     ),
     auto_range=dict(argstr='--auto_range',
-    xor=(u'image_range', u'auto_range'),
+    xor=('image_range', 'auto_range'),
     ),
     clobber=dict(argstr='-clobber',
     usedefault=True,
@@ -19,19 +20,19 @@ def test_Pik_inputs():
     usedefault=True,
     ),
     horizontal_triplanar_view=dict(argstr='--horizontal',
-    xor=(u'vertical_triplanar_view', u'horizontal_triplanar_view'),
+    xor=('vertical_triplanar_view', 'horizontal_triplanar_view'),
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
     ),
     image_range=dict(argstr='--image_range %s %s',
-    xor=(u'image_range', u'auto_range'),
+    xor=('image_range', 'auto_range'),
     ),
     input_file=dict(argstr='%s',
     mandatory=True,
     position=-2,
     ),
-    jpg=dict(xor=(u'jpg', u'png'),
+    jpg=dict(xor=('jpg', 'png'),
     ),
     lookup=dict(argstr='--lookup %s',
     ),
@@ -41,11 +42,11 @@ def test_Pik_inputs():
     genfile=True,
     hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s.png',
     position=-1,
     ),
-    png=dict(xor=(u'jpg', u'png'),
+    png=dict(xor=('jpg', 'png'),
     ),
     sagittal_offset=dict(argstr='--sagittal_offset %s',
     ),
@@ -54,13 +55,13 @@ def test_Pik_inputs():
     scale=dict(argstr='--scale %s',
     ),
     slice_x=dict(argstr='-x',
-    xor=(u'slice_z', u'slice_y', u'slice_x'),
+    xor=('slice_z', 'slice_y', 'slice_x'),
     ),
     slice_y=dict(argstr='-y',
-    xor=(u'slice_z', u'slice_y', u'slice_x'),
+    xor=('slice_z', 'slice_y', 'slice_x'),
     ),
     slice_z=dict(argstr='-z',
-    xor=(u'slice_z', u'slice_y', u'slice_x'),
+    xor=('slice_z', 'slice_y', 'slice_x'),
     ),
     start=dict(argstr='--slice %s',
     ),
@@ -71,12 +72,12 @@ def test_Pik_inputs():
     title=dict(argstr='%s',
     ),
     title_size=dict(argstr='--title_size %s',
-    requires=[u'title'],
+    requires=['title'],
     ),
     triplanar=dict(argstr='--triplanar',
     ),
     vertical_triplanar_view=dict(argstr='--vertical',
-    xor=(u'vertical_triplanar_view', u'horizontal_triplanar_view'),
+    xor=('vertical_triplanar_view', 'horizontal_triplanar_view'),
     ),
     width=dict(argstr='--width %s',
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Resample.py b/nipype/interfaces/minc/tests/test_auto_Resample.py
--- a/nipype/interfaces/minc/tests/test_auto_Resample.py
+++ b/nipype/interfaces/minc/tests/test_auto_Resample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Resample
 
 
@@ -9,46 +10,46 @@ def test_Resample_inputs():
     usedefault=True,
     ),
     coronal_slices=dict(argstr='-coronal',
-    xor=(u'transverse', u'sagittal', u'coronal'),
+    xor=('transverse', 'sagittal', 'coronal'),
     ),
     dircos=dict(argstr='-dircos %s %s %s',
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     environ=dict(nohash=True,
     usedefault=True,
     ),
     fill=dict(argstr='-fill',
-    xor=(u'nofill', u'fill'),
+    xor=('nofill', 'fill'),
     ),
     fill_value=dict(argstr='-fillvalue %s',
-    requires=[u'fill'],
+    requires=['fill'],
     ),
     format_byte=dict(argstr='-byte',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_double=dict(argstr='-double',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_float=dict(argstr='-float',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_int=dict(argstr='-int',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_long=dict(argstr='-long',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_short=dict(argstr='-short',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_signed=dict(argstr='-signed',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     format_unsigned=dict(argstr='-unsigned',
-    xor=(u'format_byte', u'format_short', u'format_int', u'format_long', u'format_float', u'format_double', u'format_signed', u'format_unsigned'),
+    xor=('format_byte', 'format_short', 'format_int', 'format_long', 'format_float', 'format_double', 'format_signed', 'format_unsigned'),
     ),
     half_width_sinc_window=dict(argstr='-width %s',
-    requires=[u'sinc_interpolation'],
+    requires=['sinc_interpolation'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -61,59 +62,59 @@ def test_Resample_inputs():
     invert_transformation=dict(argstr='-invert_transformation',
     ),
     keep_real_range=dict(argstr='-keep_real_range',
-    xor=(u'keep_real_range', u'nokeep_real_range'),
+    xor=('keep_real_range', 'nokeep_real_range'),
     ),
     like=dict(argstr='-like %s',
     ),
     nearest_neighbour_interpolation=dict(argstr='-nearest_neighbour',
-    xor=(u'trilinear_interpolation', u'tricubic_interpolation', u'nearest_neighbour_interpolation', u'sinc_interpolation'),
+    xor=('trilinear_interpolation', 'tricubic_interpolation', 'nearest_neighbour_interpolation', 'sinc_interpolation'),
     ),
     nelements=dict(argstr='-nelements %s %s %s',
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     no_fill=dict(argstr='-nofill',
-    xor=(u'nofill', u'fill'),
+    xor=('nofill', 'fill'),
     ),
     no_input_sampling=dict(argstr='-use_input_sampling',
-    xor=(u'vio_transform', u'no_input_sampling'),
+    xor=('vio_transform', 'no_input_sampling'),
     ),
     nokeep_real_range=dict(argstr='-nokeep_real_range',
-    xor=(u'keep_real_range', u'nokeep_real_range'),
+    xor=('keep_real_range', 'nokeep_real_range'),
     ),
     origin=dict(argstr='-origin %s %s %s',
     ),
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_resample.mnc',
     position=-1,
     ),
     output_range=dict(argstr='-range %s %s',
     ),
     sagittal_slices=dict(argstr='-sagittal',
-    xor=(u'transverse', u'sagittal', u'coronal'),
+    xor=('transverse', 'sagittal', 'coronal'),
     ),
     sinc_interpolation=dict(argstr='-sinc',
-    xor=(u'trilinear_interpolation', u'tricubic_interpolation', u'nearest_neighbour_interpolation', u'sinc_interpolation'),
+    xor=('trilinear_interpolation', 'tricubic_interpolation', 'nearest_neighbour_interpolation', 'sinc_interpolation'),
     ),
     sinc_window_hamming=dict(argstr='-hamming',
-    requires=[u'sinc_interpolation'],
-    xor=(u'sinc_window_hanning', u'sinc_window_hamming'),
+    requires=['sinc_interpolation'],
+    xor=('sinc_window_hanning', 'sinc_window_hamming'),
     ),
     sinc_window_hanning=dict(argstr='-hanning',
-    requires=[u'sinc_interpolation'],
-    xor=(u'sinc_window_hanning', u'sinc_window_hamming'),
+    requires=['sinc_interpolation'],
+    xor=('sinc_window_hanning', 'sinc_window_hamming'),
     ),
     spacetype=dict(argstr='-spacetype %s',
     ),
     standard_sampling=dict(argstr='-standard_sampling',
     ),
     start=dict(argstr='-start %s %s %s',
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     step=dict(argstr='-step %s %s %s',
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     talairach=dict(argstr='-talairach',
     ),
@@ -122,68 +123,68 @@ def test_Resample_inputs():
     transformation=dict(argstr='-transformation %s',
     ),
     transverse_slices=dict(argstr='-transverse',
-    xor=(u'transverse', u'sagittal', u'coronal'),
+    xor=('transverse', 'sagittal', 'coronal'),
     ),
     tricubic_interpolation=dict(argstr='-tricubic',
-    xor=(u'trilinear_interpolation', u'tricubic_interpolation', u'nearest_neighbour_interpolation', u'sinc_interpolation'),
+    xor=('trilinear_interpolation', 'tricubic_interpolation', 'nearest_neighbour_interpolation', 'sinc_interpolation'),
     ),
     trilinear_interpolation=dict(argstr='-trilinear',
-    xor=(u'trilinear_interpolation', u'tricubic_interpolation', u'nearest_neighbour_interpolation', u'sinc_interpolation'),
+    xor=('trilinear_interpolation', 'tricubic_interpolation', 'nearest_neighbour_interpolation', 'sinc_interpolation'),
     ),
     two=dict(argstr='-2',
     ),
     units=dict(argstr='-units %s',
     ),
     vio_transform=dict(argstr='-tfm_input_sampling',
-    xor=(u'vio_transform', u'no_input_sampling'),
+    xor=('vio_transform', 'no_input_sampling'),
     ),
     xdircos=dict(argstr='-xdircos %s',
-    requires=(u'ydircos', u'zdircos'),
-    xor=(u'dircos', u'dircos_x_y_or_z'),
+    requires=('ydircos', 'zdircos'),
+    xor=('dircos', 'dircos_x_y_or_z'),
     ),
     xnelements=dict(argstr='-xnelements %s',
-    requires=(u'ynelements', u'znelements'),
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    requires=('ynelements', 'znelements'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     xstart=dict(argstr='-xstart %s',
-    requires=(u'ystart', u'zstart'),
-    xor=(u'start', u'start_x_y_or_z'),
+    requires=('ystart', 'zstart'),
+    xor=('start', 'start_x_y_or_z'),
     ),
     xstep=dict(argstr='-xstep %s',
-    requires=(u'ystep', u'zstep'),
-    xor=(u'step', u'step_x_y_or_z'),
+    requires=('ystep', 'zstep'),
+    xor=('step', 'step_x_y_or_z'),
     ),
     ydircos=dict(argstr='-ydircos %s',
-    requires=(u'xdircos', u'zdircos'),
-    xor=(u'dircos', u'dircos_x_y_or_z'),
+    requires=('xdircos', 'zdircos'),
+    xor=('dircos', 'dircos_x_y_or_z'),
     ),
     ynelements=dict(argstr='-ynelements %s',
-    requires=(u'xnelements', u'znelements'),
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    requires=('xnelements', 'znelements'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     ystart=dict(argstr='-ystart %s',
-    requires=(u'xstart', u'zstart'),
-    xor=(u'start', u'start_x_y_or_z'),
+    requires=('xstart', 'zstart'),
+    xor=('start', 'start_x_y_or_z'),
     ),
     ystep=dict(argstr='-ystep %s',
-    requires=(u'xstep', u'zstep'),
-    xor=(u'step', u'step_x_y_or_z'),
+    requires=('xstep', 'zstep'),
+    xor=('step', 'step_x_y_or_z'),
     ),
     zdircos=dict(argstr='-zdircos %s',
-    requires=(u'xdircos', u'ydircos'),
-    xor=(u'dircos', u'dircos_x_y_or_z'),
+    requires=('xdircos', 'ydircos'),
+    xor=('dircos', 'dircos_x_y_or_z'),
     ),
     znelements=dict(argstr='-znelements %s',
-    requires=(u'xnelements', u'ynelements'),
-    xor=(u'nelements', u'nelements_x_y_or_z'),
+    requires=('xnelements', 'ynelements'),
+    xor=('nelements', 'nelements_x_y_or_z'),
     ),
     zstart=dict(argstr='-zstart %s',
-    requires=(u'xstart', u'ystart'),
-    xor=(u'start', u'start_x_y_or_z'),
+    requires=('xstart', 'ystart'),
+    xor=('start', 'start_x_y_or_z'),
     ),
     zstep=dict(argstr='-zstep %s',
-    requires=(u'xstep', u'ystep'),
-    xor=(u'step', u'step_x_y_or_z'),
+    requires=('xstep', 'ystep'),
+    xor=('step', 'step_x_y_or_z'),
     ),
     )
     inputs = Resample.input_spec()
diff --git a/nipype/interfaces/minc/tests/test_auto_Reshape.py b/nipype/interfaces/minc/tests/test_auto_Reshape.py
--- a/nipype/interfaces/minc/tests/test_auto_Reshape.py
+++ b/nipype/interfaces/minc/tests/test_auto_Reshape.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Reshape
 
 
@@ -21,7 +22,7 @@ def test_Reshape_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_reshape.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_ToEcat.py b/nipype/interfaces/minc/tests/test_auto_ToEcat.py
--- a/nipype/interfaces/minc/tests/test_auto_ToEcat.py
+++ b/nipype/interfaces/minc/tests/test_auto_ToEcat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import ToEcat
 
 
@@ -33,7 +34,7 @@ def test_ToEcat_inputs():
     genfile=True,
     hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_to_ecat.v',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_ToRaw.py b/nipype/interfaces/minc/tests/test_auto_ToRaw.py
--- a/nipype/interfaces/minc/tests/test_auto_ToRaw.py
+++ b/nipype/interfaces/minc/tests/test_auto_ToRaw.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import ToRaw
 
 
@@ -16,10 +17,10 @@ def test_ToRaw_inputs():
     position=-2,
     ),
     nonormalize=dict(argstr='-nonormalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     normalize=dict(argstr='-normalize',
-    xor=(u'normalize', u'nonormalize'),
+    xor=('normalize', 'nonormalize'),
     ),
     out_file=dict(argstr='> %s',
     genfile=True,
@@ -27,37 +28,37 @@ def test_ToRaw_inputs():
     ),
     output_file=dict(hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s.raw',
     position=-1,
     ),
     terminal_output=dict(nohash=True,
     ),
     write_byte=dict(argstr='-byte',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_double=dict(argstr='-double',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_float=dict(argstr='-float',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_int=dict(argstr='-int',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_long=dict(argstr='-long',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_range=dict(argstr='-range %s %s',
     ),
     write_short=dict(argstr='-short',
-    xor=(u'write_byte', u'write_short', u'write_int', u'write_long', u'write_float', u'write_double'),
+    xor=('write_byte', 'write_short', 'write_int', 'write_long', 'write_float', 'write_double'),
     ),
     write_signed=dict(argstr='-signed',
-    xor=(u'write_signed', u'write_unsigned'),
+    xor=('write_signed', 'write_unsigned'),
     ),
     write_unsigned=dict(argstr='-unsigned',
-    xor=(u'write_signed', u'write_unsigned'),
+    xor=('write_signed', 'write_unsigned'),
     ),
     )
     inputs = ToRaw.input_spec()
diff --git a/nipype/interfaces/minc/tests/test_auto_VolSymm.py b/nipype/interfaces/minc/tests/test_auto_VolSymm.py
--- a/nipype/interfaces/minc/tests/test_auto_VolSymm.py
+++ b/nipype/interfaces/minc/tests/test_auto_VolSymm.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import VolSymm
 
 
@@ -30,7 +31,7 @@ def test_VolSymm_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_vol_symm.mnc',
     position=-1,
     ),
@@ -40,7 +41,7 @@ def test_VolSymm_inputs():
     genfile=True,
     hash_files=False,
     keep_extension=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_vol_symm.xfm',
     position=-2,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Volcentre.py b/nipype/interfaces/minc/tests/test_auto_Volcentre.py
--- a/nipype/interfaces/minc/tests/test_auto_Volcentre.py
+++ b/nipype/interfaces/minc/tests/test_auto_Volcentre.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Volcentre
 
 
@@ -25,7 +26,7 @@ def test_Volcentre_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_volcentre.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Voliso.py b/nipype/interfaces/minc/tests/test_auto_Voliso.py
--- a/nipype/interfaces/minc/tests/test_auto_Voliso.py
+++ b/nipype/interfaces/minc/tests/test_auto_Voliso.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Voliso
 
 
@@ -27,7 +28,7 @@ def test_Voliso_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_voliso.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_Volpad.py b/nipype/interfaces/minc/tests/test_auto_Volpad.py
--- a/nipype/interfaces/minc/tests/test_auto_Volpad.py
+++ b/nipype/interfaces/minc/tests/test_auto_Volpad.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import Volpad
 
 
@@ -27,7 +28,7 @@ def test_Volpad_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_file'],
+    name_source=['input_file'],
     name_template='%s_volpad.mnc',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_XfmAvg.py b/nipype/interfaces/minc/tests/test_auto_XfmAvg.py
--- a/nipype/interfaces/minc/tests/test_auto_XfmAvg.py
+++ b/nipype/interfaces/minc/tests/test_auto_XfmAvg.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import XfmAvg
 
 
diff --git a/nipype/interfaces/minc/tests/test_auto_XfmConcat.py b/nipype/interfaces/minc/tests/test_auto_XfmConcat.py
--- a/nipype/interfaces/minc/tests/test_auto_XfmConcat.py
+++ b/nipype/interfaces/minc/tests/test_auto_XfmConcat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import XfmConcat
 
 
@@ -23,7 +24,7 @@ def test_XfmConcat_inputs():
     output_file=dict(argstr='%s',
     genfile=True,
     hash_files=False,
-    name_source=[u'input_files'],
+    name_source=['input_files'],
     name_template='%s_xfmconcat.xfm',
     position=-1,
     ),
diff --git a/nipype/interfaces/minc/tests/test_auto_XfmInvert.py b/nipype/interfaces/minc/tests/test_auto_XfmInvert.py
--- a/nipype/interfaces/minc/tests/test_auto_XfmInvert.py
+++ b/nipype/interfaces/minc/tests/test_auto_XfmInvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..minc import XfmInvert
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistBrainMgdmSegmentation.py b/nipype/interfaces/mipav/tests/test_auto_JistBrainMgdmSegmentation.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistBrainMgdmSegmentation.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistBrainMgdmSegmentation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistBrainMgdmSegmentation
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageDuraEstimation.py b/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageDuraEstimation.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageDuraEstimation.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageDuraEstimation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistBrainMp2rageDuraEstimation
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageSkullStripping.py b/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageSkullStripping.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageSkullStripping.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistBrainMp2rageSkullStripping.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistBrainMp2rageSkullStripping
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistBrainPartialVolumeFilter.py b/nipype/interfaces/mipav/tests/test_auto_JistBrainPartialVolumeFilter.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistBrainPartialVolumeFilter.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistBrainPartialVolumeFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistBrainPartialVolumeFilter
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistCortexSurfaceMeshInflation.py b/nipype/interfaces/mipav/tests/test_auto_JistCortexSurfaceMeshInflation.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistCortexSurfaceMeshInflation.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistCortexSurfaceMeshInflation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistCortexSurfaceMeshInflation
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistIntensityMp2rageMasking.py b/nipype/interfaces/mipav/tests/test_auto_JistIntensityMp2rageMasking.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistIntensityMp2rageMasking.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistIntensityMp2rageMasking.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistIntensityMp2rageMasking
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileCalculator.py b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileCalculator.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileCalculator.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileCalculator.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistLaminarProfileCalculator
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileGeometry.py b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileGeometry.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileGeometry.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileGeometry.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistLaminarProfileGeometry
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileSampling.py b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileSampling.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileSampling.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistLaminarProfileSampling.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistLaminarProfileSampling
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistLaminarROIAveraging.py b/nipype/interfaces/mipav/tests/test_auto_JistLaminarROIAveraging.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistLaminarROIAveraging.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistLaminarROIAveraging.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistLaminarROIAveraging
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_JistLaminarVolumetricLayering.py b/nipype/interfaces/mipav/tests/test_auto_JistLaminarVolumetricLayering.py
--- a/nipype/interfaces/mipav/tests/test_auto_JistLaminarVolumetricLayering.py
+++ b/nipype/interfaces/mipav/tests/test_auto_JistLaminarVolumetricLayering.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import JistLaminarVolumetricLayering
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmImageCalculator.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmImageCalculator.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmImageCalculator.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmImageCalculator.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmImageCalculator
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmLesionToads.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmLesionToads.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmLesionToads.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmLesionToads.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmLesionToads
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmMipavReorient.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmMipavReorient.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmMipavReorient.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmMipavReorient.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmMipavReorient
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmN3.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmN3.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmN3.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmN3.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmN3
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmSPECTRE2010.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmSPECTRE2010.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmSPECTRE2010.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmSPECTRE2010.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmSPECTRE2010
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmThresholdToBinaryMask.py b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmThresholdToBinaryMask.py
--- a/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmThresholdToBinaryMask.py
+++ b/nipype/interfaces/mipav/tests/test_auto_MedicAlgorithmThresholdToBinaryMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import MedicAlgorithmThresholdToBinaryMask
 
 
diff --git a/nipype/interfaces/mipav/tests/test_auto_RandomVol.py b/nipype/interfaces/mipav/tests/test_auto_RandomVol.py
--- a/nipype/interfaces/mipav/tests/test_auto_RandomVol.py
+++ b/nipype/interfaces/mipav/tests/test_auto_RandomVol.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..developer import RandomVol
 
 
diff --git a/nipype/interfaces/mne/tests/test_auto_WatershedBEM.py b/nipype/interfaces/mne/tests/test_auto_WatershedBEM.py
--- a/nipype/interfaces/mne/tests/test_auto_WatershedBEM.py
+++ b/nipype/interfaces/mne/tests/test_auto_WatershedBEM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import WatershedBEM
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_ConstrainedSphericalDeconvolution.py b/nipype/interfaces/mrtrix/tests/test_auto_ConstrainedSphericalDeconvolution.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_ConstrainedSphericalDeconvolution.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_ConstrainedSphericalDeconvolution.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import ConstrainedSphericalDeconvolution
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_DWI2SphericalHarmonicsImage.py b/nipype/interfaces/mrtrix/tests/test_auto_DWI2SphericalHarmonicsImage.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_DWI2SphericalHarmonicsImage.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_DWI2SphericalHarmonicsImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import DWI2SphericalHarmonicsImage
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_DWI2Tensor.py b/nipype/interfaces/mrtrix/tests/test_auto_DWI2Tensor.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_DWI2Tensor.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_DWI2Tensor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import DWI2Tensor
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_DiffusionTensorStreamlineTrack.py b/nipype/interfaces/mrtrix/tests/test_auto_DiffusionTensorStreamlineTrack.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_DiffusionTensorStreamlineTrack.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_DiffusionTensorStreamlineTrack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import DiffusionTensorStreamlineTrack
 
 
@@ -16,13 +17,13 @@ def test_DiffusionTensorStreamlineTrack_inputs():
     usedefault=True,
     ),
     exclude_file=dict(argstr='-exclude %s',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     exclude_spec=dict(argstr='-exclude %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     gradient_encoding_file=dict(argstr='-grad %s',
     mandatory=True,
@@ -36,13 +37,13 @@ def test_DiffusionTensorStreamlineTrack_inputs():
     position=-2,
     ),
     include_file=dict(argstr='-include %s',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     include_spec=dict(argstr='-include %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     initial_cutoff_value=dict(argstr='-initcutoff %s',
     units='NA',
@@ -55,13 +56,13 @@ def test_DiffusionTensorStreamlineTrack_inputs():
     usedefault=True,
     ),
     mask_file=dict(argstr='-mask %s',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     mask_spec=dict(argstr='-mask %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     maximum_number_of_tracks=dict(argstr='-maxnum %d',
     ),
@@ -77,19 +78,19 @@ def test_DiffusionTensorStreamlineTrack_inputs():
     no_mask_interpolation=dict(argstr='-nomaskinterp',
     ),
     out_file=dict(argstr='%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tracked.tck',
     output_name='tracked',
     position=-1,
     ),
     seed_file=dict(argstr='-seed %s',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     seed_spec=dict(argstr='-seed %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     step_size=dict(argstr='-step %s',
     units='mm',
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Directions2Amplitude.py b/nipype/interfaces/mrtrix/tests/test_auto_Directions2Amplitude.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Directions2Amplitude.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Directions2Amplitude.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import Directions2Amplitude
 
 
@@ -24,7 +25,7 @@ def test_Directions2Amplitude_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_amplitudes.mif',
     position=-1,
     ),
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Erode.py b/nipype/interfaces/mrtrix/tests/test_auto_Erode.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Erode.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Erode.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Erode
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_EstimateResponseForSH.py b/nipype/interfaces/mrtrix/tests/test_auto_EstimateResponseForSH.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_EstimateResponseForSH.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_EstimateResponseForSH.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import EstimateResponseForSH
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_FSL2MRTrix.py b/nipype/interfaces/mrtrix/tests/test_auto_FSL2MRTrix.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_FSL2MRTrix.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_FSL2MRTrix.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import FSL2MRTrix
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_FilterTracks.py b/nipype/interfaces/mrtrix/tests/test_auto_FilterTracks.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_FilterTracks.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_FilterTracks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import FilterTracks
 
 
@@ -12,13 +13,13 @@ def test_FilterTracks_inputs():
     usedefault=True,
     ),
     exclude_file=dict(argstr='-exclude %s',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     exclude_spec=dict(argstr='-exclude %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -28,13 +29,13 @@ def test_FilterTracks_inputs():
     position=-2,
     ),
     include_file=dict(argstr='-include %s',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     include_spec=dict(argstr='-include %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     invert=dict(argstr='-invert',
     ),
@@ -45,7 +46,7 @@ def test_FilterTracks_inputs():
     ),
     out_file=dict(argstr='%s',
     hash_files=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_filt',
     position=-1,
     ),
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_FindShPeaks.py b/nipype/interfaces/mrtrix/tests/test_auto_FindShPeaks.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_FindShPeaks.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_FindShPeaks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import FindShPeaks
 
 
@@ -28,7 +29,7 @@ def test_FindShPeaks_inputs():
     out_file=dict(argstr='%s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_peak_dirs.mif',
     position=-1,
     ),
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_GenerateDirections.py b/nipype/interfaces/mrtrix/tests/test_auto_GenerateDirections.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_GenerateDirections.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_GenerateDirections.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tensors import GenerateDirections
 
 
@@ -23,7 +24,7 @@ def test_GenerateDirections_inputs():
     ),
     out_file=dict(argstr='%s',
     hash_files=False,
-    name_source=[u'num_dirs'],
+    name_source=['num_dirs'],
     name_template='directions_%d.txt',
     position=-1,
     ),
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_GenerateWhiteMatterMask.py b/nipype/interfaces/mrtrix/tests/test_auto_GenerateWhiteMatterMask.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_GenerateWhiteMatterMask.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_GenerateWhiteMatterMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import GenerateWhiteMatterMask
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRConvert.py b/nipype/interfaces/mrtrix/tests/test_auto_MRConvert.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRConvert.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRConvert
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRMultiply.py b/nipype/interfaces/mrtrix/tests/test_auto_MRMultiply.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRMultiply.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRMultiply.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRMultiply
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRTransform.py b/nipype/interfaces/mrtrix/tests/test_auto_MRTransform.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRTransform.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRTransform
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRTrix2TrackVis.py b/nipype/interfaces/mrtrix/tests/test_auto_MRTrix2TrackVis.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRTrix2TrackVis.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRTrix2TrackVis.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..convert import MRTrix2TrackVis
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRTrixInfo.py b/nipype/interfaces/mrtrix/tests/test_auto_MRTrixInfo.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRTrixInfo.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRTrixInfo.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRTrixInfo
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MRTrixViewer.py b/nipype/interfaces/mrtrix/tests/test_auto_MRTrixViewer.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MRTrixViewer.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MRTrixViewer.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MRTrixViewer
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_MedianFilter3D.py b/nipype/interfaces/mrtrix/tests/test_auto_MedianFilter3D.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_MedianFilter3D.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_MedianFilter3D.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import MedianFilter3D
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_ProbabilisticSphericallyDeconvolutedStreamlineTrack.py b/nipype/interfaces/mrtrix/tests/test_auto_ProbabilisticSphericallyDeconvolutedStreamlineTrack.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_ProbabilisticSphericallyDeconvolutedStreamlineTrack.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_ProbabilisticSphericallyDeconvolutedStreamlineTrack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import ProbabilisticSphericallyDeconvolutedStreamlineTrack
 
 
@@ -16,13 +17,13 @@ def test_ProbabilisticSphericallyDeconvolutedStreamlineTrack_inputs():
     usedefault=True,
     ),
     exclude_file=dict(argstr='-exclude %s',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     exclude_spec=dict(argstr='-exclude %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -32,13 +33,13 @@ def test_ProbabilisticSphericallyDeconvolutedStreamlineTrack_inputs():
     position=-2,
     ),
     include_file=dict(argstr='-include %s',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     include_spec=dict(argstr='-include %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     initial_cutoff_value=dict(argstr='-initcutoff %s',
     units='NA',
@@ -51,13 +52,13 @@ def test_ProbabilisticSphericallyDeconvolutedStreamlineTrack_inputs():
     usedefault=True,
     ),
     mask_file=dict(argstr='-mask %s',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     mask_spec=dict(argstr='-mask %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     maximum_number_of_tracks=dict(argstr='-maxnum %d',
     ),
@@ -75,19 +76,19 @@ def test_ProbabilisticSphericallyDeconvolutedStreamlineTrack_inputs():
     no_mask_interpolation=dict(argstr='-nomaskinterp',
     ),
     out_file=dict(argstr='%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tracked.tck',
     output_name='tracked',
     position=-1,
     ),
     seed_file=dict(argstr='-seed %s',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     seed_spec=dict(argstr='-seed %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     step_size=dict(argstr='-step %s',
     units='mm',
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_SphericallyDeconvolutedStreamlineTrack.py b/nipype/interfaces/mrtrix/tests/test_auto_SphericallyDeconvolutedStreamlineTrack.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_SphericallyDeconvolutedStreamlineTrack.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_SphericallyDeconvolutedStreamlineTrack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import SphericallyDeconvolutedStreamlineTrack
 
 
@@ -16,13 +17,13 @@ def test_SphericallyDeconvolutedStreamlineTrack_inputs():
     usedefault=True,
     ),
     exclude_file=dict(argstr='-exclude %s',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     exclude_spec=dict(argstr='-exclude %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -32,13 +33,13 @@ def test_SphericallyDeconvolutedStreamlineTrack_inputs():
     position=-2,
     ),
     include_file=dict(argstr='-include %s',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     include_spec=dict(argstr='-include %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     initial_cutoff_value=dict(argstr='-initcutoff %s',
     units='NA',
@@ -51,13 +52,13 @@ def test_SphericallyDeconvolutedStreamlineTrack_inputs():
     usedefault=True,
     ),
     mask_file=dict(argstr='-mask %s',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     mask_spec=dict(argstr='-mask %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     maximum_number_of_tracks=dict(argstr='-maxnum %d',
     ),
@@ -73,19 +74,19 @@ def test_SphericallyDeconvolutedStreamlineTrack_inputs():
     no_mask_interpolation=dict(argstr='-nomaskinterp',
     ),
     out_file=dict(argstr='%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tracked.tck',
     output_name='tracked',
     position=-1,
     ),
     seed_file=dict(argstr='-seed %s',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     seed_spec=dict(argstr='-seed %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     step_size=dict(argstr='-step %s',
     units='mm',
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_StreamlineTrack.py b/nipype/interfaces/mrtrix/tests/test_auto_StreamlineTrack.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_StreamlineTrack.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_StreamlineTrack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import StreamlineTrack
 
 
@@ -16,13 +17,13 @@ def test_StreamlineTrack_inputs():
     usedefault=True,
     ),
     exclude_file=dict(argstr='-exclude %s',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     exclude_spec=dict(argstr='-exclude %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'exclude_file', u'exclude_spec'],
+    xor=['exclude_file', 'exclude_spec'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -32,13 +33,13 @@ def test_StreamlineTrack_inputs():
     position=-2,
     ),
     include_file=dict(argstr='-include %s',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     include_spec=dict(argstr='-include %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'include_file', u'include_spec'],
+    xor=['include_file', 'include_spec'],
     ),
     initial_cutoff_value=dict(argstr='-initcutoff %s',
     units='NA',
@@ -51,13 +52,13 @@ def test_StreamlineTrack_inputs():
     usedefault=True,
     ),
     mask_file=dict(argstr='-mask %s',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     mask_spec=dict(argstr='-mask %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'mask_file', u'mask_spec'],
+    xor=['mask_file', 'mask_spec'],
     ),
     maximum_number_of_tracks=dict(argstr='-maxnum %d',
     ),
@@ -73,19 +74,19 @@ def test_StreamlineTrack_inputs():
     no_mask_interpolation=dict(argstr='-nomaskinterp',
     ),
     out_file=dict(argstr='%s',
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s_tracked.tck',
     output_name='tracked',
     position=-1,
     ),
     seed_file=dict(argstr='-seed %s',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     seed_spec=dict(argstr='-seed %s',
     position=2,
     sep=',',
     units='mm',
-    xor=[u'seed_file', u'seed_spec'],
+    xor=['seed_file', 'seed_spec'],
     ),
     step_size=dict(argstr='-step %s',
     units='mm',
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2ApparentDiffusion.py b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2ApparentDiffusion.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2ApparentDiffusion.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2ApparentDiffusion.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Tensor2ApparentDiffusion
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2FractionalAnisotropy.py b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2FractionalAnisotropy.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2FractionalAnisotropy.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2FractionalAnisotropy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Tensor2FractionalAnisotropy
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2Vector.py b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2Vector.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Tensor2Vector.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Tensor2Vector.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Tensor2Vector
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Threshold.py b/nipype/interfaces/mrtrix/tests/test_auto_Threshold.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Threshold.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Threshold.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Threshold
 
 
diff --git a/nipype/interfaces/mrtrix/tests/test_auto_Tracks2Prob.py b/nipype/interfaces/mrtrix/tests/test_auto_Tracks2Prob.py
--- a/nipype/interfaces/mrtrix/tests/test_auto_Tracks2Prob.py
+++ b/nipype/interfaces/mrtrix/tests/test_auto_Tracks2Prob.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import Tracks2Prob
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_ACTPrepareFSL.py b/nipype/interfaces/mrtrix3/tests/test_auto_ACTPrepareFSL.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_ACTPrepareFSL.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_ACTPrepareFSL.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ACTPrepareFSL
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_BrainMask.py b/nipype/interfaces/mrtrix3/tests/test_auto_BrainMask.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_BrainMask.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_BrainMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import BrainMask
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_BuildConnectome.py b/nipype/interfaces/mrtrix3/tests/test_auto_BuildConnectome.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_BuildConnectome.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_BuildConnectome.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..connectivity import BuildConnectome
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_ComputeTDI.py b/nipype/interfaces/mrtrix3/tests/test_auto_ComputeTDI.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_ComputeTDI.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_ComputeTDI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ComputeTDI
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_EstimateFOD.py b/nipype/interfaces/mrtrix3/tests/test_auto_EstimateFOD.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_EstimateFOD.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_EstimateFOD.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..reconst import EstimateFOD
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_FitTensor.py b/nipype/interfaces/mrtrix3/tests/test_auto_FitTensor.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_FitTensor.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_FitTensor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..reconst import FitTensor
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_Generate5tt.py b/nipype/interfaces/mrtrix3/tests/test_auto_Generate5tt.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_Generate5tt.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_Generate5tt.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Generate5tt
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_LabelConfig.py b/nipype/interfaces/mrtrix3/tests/test_auto_LabelConfig.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_LabelConfig.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_LabelConfig.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..connectivity import LabelConfig
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_MRTrix3Base.py b/nipype/interfaces/mrtrix3/tests/test_auto_MRTrix3Base.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_MRTrix3Base.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_MRTrix3Base.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import MRTrix3Base
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_Mesh2PVE.py b/nipype/interfaces/mrtrix3/tests/test_auto_Mesh2PVE.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_Mesh2PVE.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_Mesh2PVE.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Mesh2PVE
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_ReplaceFSwithFIRST.py b/nipype/interfaces/mrtrix3/tests/test_auto_ReplaceFSwithFIRST.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_ReplaceFSwithFIRST.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_ReplaceFSwithFIRST.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ReplaceFSwithFIRST
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py b/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_ResponseSD.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ResponseSD
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_TCK2VTK.py b/nipype/interfaces/mrtrix3/tests/test_auto_TCK2VTK.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_TCK2VTK.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_TCK2VTK.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TCK2VTK
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py b/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_TensorMetrics.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import TensorMetrics
 
 
diff --git a/nipype/interfaces/mrtrix3/tests/test_auto_Tractography.py b/nipype/interfaces/mrtrix3/tests/test_auto_Tractography.py
--- a/nipype/interfaces/mrtrix3/tests/test_auto_Tractography.py
+++ b/nipype/interfaces/mrtrix3/tests/test_auto_Tractography.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..tracking import Tractography
 
 
@@ -80,17 +81,17 @@ def test_Tractography_inputs():
     seed_dynamic=dict(argstr='-seed_dynamic %s',
     ),
     seed_gmwmi=dict(argstr='-seed_gmwmi %s',
-    requires=[u'act_file'],
+    requires=['act_file'],
     ),
     seed_grid_voxel=dict(argstr='-seed_grid_per_voxel %s %d',
-    xor=[u'seed_image', u'seed_rnd_voxel'],
+    xor=['seed_image', 'seed_rnd_voxel'],
     ),
     seed_image=dict(argstr='-seed_image %s',
     ),
     seed_rejection=dict(argstr='-seed_rejection %s',
     ),
     seed_rnd_voxel=dict(argstr='-seed_random_per_voxel %s %d',
-    xor=[u'seed_image', u'seed_grid_voxel'],
+    xor=['seed_image', 'seed_grid_voxel'],
     ),
     seed_sphere=dict(argstr='-seed_sphere %f,%f,%f,%f',
     ),
diff --git a/nipype/interfaces/nipy/tests/test_auto_ComputeMask.py b/nipype/interfaces/nipy/tests/test_auto_ComputeMask.py
--- a/nipype/interfaces/nipy/tests/test_auto_ComputeMask.py
+++ b/nipype/interfaces/nipy/tests/test_auto_ComputeMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ComputeMask
 
 
diff --git a/nipype/interfaces/nipy/tests/test_auto_EstimateContrast.py b/nipype/interfaces/nipy/tests/test_auto_EstimateContrast.py
--- a/nipype/interfaces/nipy/tests/test_auto_EstimateContrast.py
+++ b/nipype/interfaces/nipy/tests/test_auto_EstimateContrast.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import EstimateContrast
 
 
diff --git a/nipype/interfaces/nipy/tests/test_auto_FitGLM.py b/nipype/interfaces/nipy/tests/test_auto_FitGLM.py
--- a/nipype/interfaces/nipy/tests/test_auto_FitGLM.py
+++ b/nipype/interfaces/nipy/tests/test_auto_FitGLM.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FitGLM
 
 
diff --git a/nipype/interfaces/nipy/tests/test_auto_FmriRealign4d.py b/nipype/interfaces/nipy/tests/test_auto_FmriRealign4d.py
--- a/nipype/interfaces/nipy/tests/test_auto_FmriRealign4d.py
+++ b/nipype/interfaces/nipy/tests/test_auto_FmriRealign4d.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import FmriRealign4d
 
 
@@ -12,17 +13,17 @@ def test_FmriRealign4d_inputs():
     ),
     loops=dict(usedefault=True,
     ),
-    slice_order=dict(requires=[u'time_interp'],
+    slice_order=dict(requires=['time_interp'],
     ),
     speedup=dict(usedefault=True,
     ),
     start=dict(usedefault=True,
     ),
-    time_interp=dict(requires=[u'slice_order'],
+    time_interp=dict(requires=['slice_order'],
     ),
     tr=dict(mandatory=True,
     ),
-    tr_slices=dict(requires=[u'time_interp'],
+    tr_slices=dict(requires=['time_interp'],
     ),
     )
     inputs = FmriRealign4d.input_spec()
diff --git a/nipype/interfaces/nipy/tests/test_auto_Similarity.py b/nipype/interfaces/nipy/tests/test_auto_Similarity.py
--- a/nipype/interfaces/nipy/tests/test_auto_Similarity.py
+++ b/nipype/interfaces/nipy/tests/test_auto_Similarity.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Similarity
 
 
diff --git a/nipype/interfaces/nipy/tests/test_auto_SpaceTimeRealigner.py b/nipype/interfaces/nipy/tests/test_auto_SpaceTimeRealigner.py
--- a/nipype/interfaces/nipy/tests/test_auto_SpaceTimeRealigner.py
+++ b/nipype/interfaces/nipy/tests/test_auto_SpaceTimeRealigner.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SpaceTimeRealigner
 
 
@@ -9,10 +10,10 @@ def test_SpaceTimeRealigner_inputs():
     in_file=dict(mandatory=True,
     min_ver='0.4.0.dev',
     ),
-    slice_info=dict(requires=[u'slice_times'],
+    slice_info=dict(requires=['slice_times'],
     ),
     slice_times=dict(),
-    tr=dict(requires=[u'slice_times'],
+    tr=dict(requires=['slice_times'],
     ),
     )
     inputs = SpaceTimeRealigner.input_spec()
diff --git a/nipype/interfaces/nipy/tests/test_auto_Trim.py b/nipype/interfaces/nipy/tests/test_auto_Trim.py
--- a/nipype/interfaces/nipy/tests/test_auto_Trim.py
+++ b/nipype/interfaces/nipy/tests/test_auto_Trim.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Trim
 
 
diff --git a/nipype/interfaces/nitime/tests/test_auto_CoherenceAnalyzer.py b/nipype/interfaces/nitime/tests/test_auto_CoherenceAnalyzer.py
--- a/nipype/interfaces/nitime/tests/test_auto_CoherenceAnalyzer.py
+++ b/nipype/interfaces/nitime/tests/test_auto_CoherenceAnalyzer.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..analysis import CoherenceAnalyzer
 
 
@@ -14,7 +15,7 @@ def test_CoherenceAnalyzer_inputs():
     usedefault=True,
     ),
     in_TS=dict(),
-    in_file=dict(requires=(u'TR',),
+    in_file=dict(requires=('TR',),
     ),
     n_overlap=dict(usedefault=True,
     ),
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSPosteriorToContinuousClass.py b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSPosteriorToContinuousClass.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSPosteriorToContinuousClass.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSPosteriorToContinuousClass.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..classify import BRAINSPosteriorToContinuousClass
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairach.py b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairach.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairach.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairach.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import BRAINSTalairach
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairachMask.py b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairachMask.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairachMask.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_BRAINSTalairachMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import BRAINSTalairachMask
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_GenerateEdgeMapImage.py b/nipype/interfaces/semtools/brains/tests/test_auto_GenerateEdgeMapImage.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_GenerateEdgeMapImage.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_GenerateEdgeMapImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utilities import GenerateEdgeMapImage
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_GeneratePurePlugMask.py b/nipype/interfaces/semtools/brains/tests/test_auto_GeneratePurePlugMask.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_GeneratePurePlugMask.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_GeneratePurePlugMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utilities import GeneratePurePlugMask
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_HistogramMatchingFilter.py b/nipype/interfaces/semtools/brains/tests/test_auto_HistogramMatchingFilter.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_HistogramMatchingFilter.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_HistogramMatchingFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utilities import HistogramMatchingFilter
 
 
diff --git a/nipype/interfaces/semtools/brains/tests/test_auto_SimilarityIndex.py b/nipype/interfaces/semtools/brains/tests/test_auto_SimilarityIndex.py
--- a/nipype/interfaces/semtools/brains/tests/test_auto_SimilarityIndex.py
+++ b/nipype/interfaces/semtools/brains/tests/test_auto_SimilarityIndex.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import SimilarityIndex
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_DWIConvert.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_DWIConvert.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_DWIConvert.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_DWIConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DWIConvert
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_compareTractInclusion.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_compareTractInclusion.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_compareTractInclusion.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_compareTractInclusion.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import compareTractInclusion
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiaverage.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiaverage.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiaverage.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiaverage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import dtiaverage
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiestim.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiestim.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiestim.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiestim.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import dtiestim
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiprocess.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiprocess.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiprocess.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_dtiprocess.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import dtiprocess
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_extractNrrdVectorIndex.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_extractNrrdVectorIndex.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_extractNrrdVectorIndex.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_extractNrrdVectorIndex.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import extractNrrdVectorIndex
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAnisotropyMap.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAnisotropyMap.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAnisotropyMap.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAnisotropyMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractAnisotropyMap
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAverageBvalues.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAverageBvalues.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAverageBvalues.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractAverageBvalues.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractAverageBvalues
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractClipAnisotropy.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractClipAnisotropy.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractClipAnisotropy.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractClipAnisotropy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractClipAnisotropy
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoRegAnatomy.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoRegAnatomy.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoRegAnatomy.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoRegAnatomy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractCoRegAnatomy
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractConcatDwi.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractConcatDwi.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractConcatDwi.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractConcatDwi.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractConcatDwi
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCopyImageOrientation.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCopyImageOrientation.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCopyImageOrientation.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCopyImageOrientation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractCopyImageOrientation
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoregBvalues.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoregBvalues.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoregBvalues.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCoregBvalues.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractCoregBvalues
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCostFastMarching.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCostFastMarching.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCostFastMarching.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCostFastMarching.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractCostFastMarching
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCreateGuideFiber.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCreateGuideFiber.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCreateGuideFiber.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractCreateGuideFiber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractCreateGuideFiber
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFastMarchingTracking.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFastMarchingTracking.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFastMarchingTracking.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFastMarchingTracking.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractFastMarchingTracking
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFiberTracking.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFiberTracking.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFiberTracking.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractFiberTracking.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractFiberTracking
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractImageConformity.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractImageConformity.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractImageConformity.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractImageConformity.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractImageConformity
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertBSplineTransform.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertBSplineTransform.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertBSplineTransform.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertBSplineTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractInvertBSplineTransform
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertDisplacementField.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertDisplacementField.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertDisplacementField.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertDisplacementField.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractInvertDisplacementField
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertRigidTransform.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertRigidTransform.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertRigidTransform.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractInvertRigidTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractInvertRigidTransform
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleAnisotropy.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleAnisotropy.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleAnisotropy.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleAnisotropy.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractResampleAnisotropy
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleB0.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleB0.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleB0.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleB0.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractResampleB0
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleCodeImage.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleCodeImage.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleCodeImage.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleCodeImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractResampleCodeImage
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleDWIInPlace.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleDWIInPlace.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleDWIInPlace.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleDWIInPlace.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractResampleDWIInPlace
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleFibers.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleFibers.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleFibers.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractResampleFibers.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractResampleFibers
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTensor.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTensor.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTensor.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTensor.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractTensor
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTransformToDisplacementField.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTransformToDisplacementField.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTransformToDisplacementField.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_gtractTransformToDisplacementField.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..gtract import gtractTransformToDisplacementField
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tests/test_auto_maxcurvature.py b/nipype/interfaces/semtools/diffusion/tests/test_auto_maxcurvature.py
--- a/nipype/interfaces/semtools/diffusion/tests/test_auto_maxcurvature.py
+++ b/nipype/interfaces/semtools/diffusion/tests/test_auto_maxcurvature.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..maxcurvature import maxcurvature
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_UKFTractography.py b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_UKFTractography.py
--- a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_UKFTractography.py
+++ b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_UKFTractography.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..ukftractography import UKFTractography
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberprocess.py b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberprocess.py
--- a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberprocess.py
+++ b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberprocess.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..fiberprocess import fiberprocess
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberstats.py b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberstats.py
--- a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberstats.py
+++ b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fiberstats.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..commandlineonly import fiberstats
 
 
diff --git a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fibertrack.py b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fibertrack.py
--- a/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fibertrack.py
+++ b/nipype/interfaces/semtools/diffusion/tractography/tests/test_auto_fibertrack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..fibertrack import fibertrack
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_CannyEdge.py b/nipype/interfaces/semtools/filtering/tests/test_auto_CannyEdge.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_CannyEdge.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_CannyEdge.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import CannyEdge
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_CannySegmentationLevelSetImageFilter.py b/nipype/interfaces/semtools/filtering/tests/test_auto_CannySegmentationLevelSetImageFilter.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_CannySegmentationLevelSetImageFilter.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_CannySegmentationLevelSetImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import CannySegmentationLevelSetImageFilter
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_DilateImage.py b/nipype/interfaces/semtools/filtering/tests/test_auto_DilateImage.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_DilateImage.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_DilateImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import DilateImage
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_DilateMask.py b/nipype/interfaces/semtools/filtering/tests/test_auto_DilateMask.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_DilateMask.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_DilateMask.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import DilateMask
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_DistanceMaps.py b/nipype/interfaces/semtools/filtering/tests/test_auto_DistanceMaps.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_DistanceMaps.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_DistanceMaps.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import DistanceMaps
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_DumpBinaryTrainingVectors.py b/nipype/interfaces/semtools/filtering/tests/test_auto_DumpBinaryTrainingVectors.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_DumpBinaryTrainingVectors.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_DumpBinaryTrainingVectors.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import DumpBinaryTrainingVectors
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_ErodeImage.py b/nipype/interfaces/semtools/filtering/tests/test_auto_ErodeImage.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_ErodeImage.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_ErodeImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import ErodeImage
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_FlippedDifference.py b/nipype/interfaces/semtools/filtering/tests/test_auto_FlippedDifference.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_FlippedDifference.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_FlippedDifference.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import FlippedDifference
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateBrainClippedImage.py b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateBrainClippedImage.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateBrainClippedImage.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateBrainClippedImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import GenerateBrainClippedImage
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateSummedGradientImage.py b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateSummedGradientImage.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateSummedGradientImage.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateSummedGradientImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import GenerateSummedGradientImage
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateTestImage.py b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateTestImage.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateTestImage.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_GenerateTestImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import GenerateTestImage
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_GradientAnisotropicDiffusionImageFilter.py b/nipype/interfaces/semtools/filtering/tests/test_auto_GradientAnisotropicDiffusionImageFilter.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_GradientAnisotropicDiffusionImageFilter.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_GradientAnisotropicDiffusionImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import GradientAnisotropicDiffusionImageFilter
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_HammerAttributeCreator.py b/nipype/interfaces/semtools/filtering/tests/test_auto_HammerAttributeCreator.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_HammerAttributeCreator.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_HammerAttributeCreator.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import HammerAttributeCreator
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMean.py b/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMean.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMean.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMean.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import NeighborhoodMean
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMedian.py b/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMedian.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMedian.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_NeighborhoodMedian.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import NeighborhoodMedian
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_STAPLEAnalysis.py b/nipype/interfaces/semtools/filtering/tests/test_auto_STAPLEAnalysis.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_STAPLEAnalysis.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_STAPLEAnalysis.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import STAPLEAnalysis
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_TextureFromNoiseImageFilter.py b/nipype/interfaces/semtools/filtering/tests/test_auto_TextureFromNoiseImageFilter.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_TextureFromNoiseImageFilter.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_TextureFromNoiseImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import TextureFromNoiseImageFilter
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_TextureMeasureFilter.py b/nipype/interfaces/semtools/filtering/tests/test_auto_TextureMeasureFilter.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_TextureMeasureFilter.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_TextureMeasureFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featuredetection import TextureMeasureFilter
 
 
diff --git a/nipype/interfaces/semtools/filtering/tests/test_auto_UnbiasedNonLocalMeans.py b/nipype/interfaces/semtools/filtering/tests/test_auto_UnbiasedNonLocalMeans.py
--- a/nipype/interfaces/semtools/filtering/tests/test_auto_UnbiasedNonLocalMeans.py
+++ b/nipype/interfaces/semtools/filtering/tests/test_auto_UnbiasedNonLocalMeans.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import UnbiasedNonLocalMeans
 
 
diff --git a/nipype/interfaces/semtools/legacy/tests/test_auto_scalartransform.py b/nipype/interfaces/semtools/legacy/tests/test_auto_scalartransform.py
--- a/nipype/interfaces/semtools/legacy/tests/test_auto_scalartransform.py
+++ b/nipype/interfaces/semtools/legacy/tests/test_auto_scalartransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import scalartransform
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSDemonWarp.py b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSDemonWarp.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSDemonWarp.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSDemonWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSDemonWarp
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSFit.py b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSFit.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSFit.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsfit import BRAINSFit
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResample.py b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResample.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResample.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsresample import BRAINSResample
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResize.py b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResize.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResize.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSResize.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsresize import BRAINSResize
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSTransformFromFiducials.py b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSTransformFromFiducials.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSTransformFromFiducials.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_BRAINSTransformFromFiducials.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSTransformFromFiducials
 
 
diff --git a/nipype/interfaces/semtools/registration/tests/test_auto_VBRAINSDemonWarp.py b/nipype/interfaces/semtools/registration/tests/test_auto_VBRAINSDemonWarp.py
--- a/nipype/interfaces/semtools/registration/tests/test_auto_VBRAINSDemonWarp.py
+++ b/nipype/interfaces/semtools/registration/tests/test_auto_VBRAINSDemonWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import VBRAINSDemonWarp
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSABC.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSABC.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSABC.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSABC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSABC
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSConstellationDetector.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSConstellationDetector.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSConstellationDetector.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSConstellationDetector.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSConstellationDetector
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCreateLabelMapFromProbabilityMaps.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCreateLabelMapFromProbabilityMaps.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCreateLabelMapFromProbabilityMaps.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCreateLabelMapFromProbabilityMaps.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSCreateLabelMapFromProbabilityMaps
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCut.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCut.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCut.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSCut.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSCut
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSMultiSTAPLE.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSMultiSTAPLE.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSMultiSTAPLE.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSMultiSTAPLE.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSMultiSTAPLE
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSROIAuto.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSROIAuto.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSROIAuto.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BRAINSROIAuto.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSROIAuto
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_BinaryMaskEditorBasedOnLandmarks.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_BinaryMaskEditorBasedOnLandmarks.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_BinaryMaskEditorBasedOnLandmarks.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_BinaryMaskEditorBasedOnLandmarks.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BinaryMaskEditorBasedOnLandmarks
 
 
diff --git a/nipype/interfaces/semtools/segmentation/tests/test_auto_ESLR.py b/nipype/interfaces/semtools/segmentation/tests/test_auto_ESLR.py
--- a/nipype/interfaces/semtools/segmentation/tests/test_auto_ESLR.py
+++ b/nipype/interfaces/semtools/segmentation/tests/test_auto_ESLR.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import ESLR
 
 
diff --git a/nipype/interfaces/semtools/tests/test_auto_DWICompare.py b/nipype/interfaces/semtools/tests/test_auto_DWICompare.py
--- a/nipype/interfaces/semtools/tests/test_auto_DWICompare.py
+++ b/nipype/interfaces/semtools/tests/test_auto_DWICompare.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..converters import DWICompare
 
 
diff --git a/nipype/interfaces/semtools/tests/test_auto_DWISimpleCompare.py b/nipype/interfaces/semtools/tests/test_auto_DWISimpleCompare.py
--- a/nipype/interfaces/semtools/tests/test_auto_DWISimpleCompare.py
+++ b/nipype/interfaces/semtools/tests/test_auto_DWISimpleCompare.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..converters import DWISimpleCompare
 
 
diff --git a/nipype/interfaces/semtools/tests/test_auto_GenerateCsfClippedFromClassifiedImage.py b/nipype/interfaces/semtools/tests/test_auto_GenerateCsfClippedFromClassifiedImage.py
--- a/nipype/interfaces/semtools/tests/test_auto_GenerateCsfClippedFromClassifiedImage.py
+++ b/nipype/interfaces/semtools/tests/test_auto_GenerateCsfClippedFromClassifiedImage.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..featurecreator import GenerateCsfClippedFromClassifiedImage
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSAlignMSP.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSAlignMSP.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSAlignMSP.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSAlignMSP.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSAlignMSP
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSClipInferior.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSClipInferior.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSClipInferior.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSClipInferior.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSClipInferior
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSConstellationModeler.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSConstellationModeler.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSConstellationModeler.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSConstellationModeler.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSConstellationModeler
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSEyeDetector.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSEyeDetector.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSEyeDetector.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSEyeDetector.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSEyeDetector
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSInitializedControlPoints.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSInitializedControlPoints.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSInitializedControlPoints.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSInitializedControlPoints.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSInitializedControlPoints
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLandmarkInitializer.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLandmarkInitializer.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLandmarkInitializer.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLandmarkInitializer.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSLandmarkInitializer
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLinearModelerEPCA.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLinearModelerEPCA.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLinearModelerEPCA.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLinearModelerEPCA.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSLinearModelerEPCA
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLmkTransform.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLmkTransform.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLmkTransform.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSLmkTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSLmkTransform
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSMush.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSMush.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSMush.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSMush.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSMush
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSSnapShotWriter.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSSnapShotWriter.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSSnapShotWriter.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSSnapShotWriter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSSnapShotWriter
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTransformConvert.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTransformConvert.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTransformConvert.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTransformConvert.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSTransformConvert
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTrimForegroundInDirection.py b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTrimForegroundInDirection.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTrimForegroundInDirection.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_BRAINSTrimForegroundInDirection.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import BRAINSTrimForegroundInDirection
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_CleanUpOverlapLabels.py b/nipype/interfaces/semtools/utilities/tests/test_auto_CleanUpOverlapLabels.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_CleanUpOverlapLabels.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_CleanUpOverlapLabels.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import CleanUpOverlapLabels
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_FindCenterOfBrain.py b/nipype/interfaces/semtools/utilities/tests/test_auto_FindCenterOfBrain.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_FindCenterOfBrain.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_FindCenterOfBrain.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import FindCenterOfBrain
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_GenerateLabelMapFromProbabilityMap.py b/nipype/interfaces/semtools/utilities/tests/test_auto_GenerateLabelMapFromProbabilityMap.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_GenerateLabelMapFromProbabilityMap.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_GenerateLabelMapFromProbabilityMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import GenerateLabelMapFromProbabilityMap
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_ImageRegionPlotter.py b/nipype/interfaces/semtools/utilities/tests/test_auto_ImageRegionPlotter.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_ImageRegionPlotter.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_ImageRegionPlotter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import ImageRegionPlotter
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_JointHistogram.py b/nipype/interfaces/semtools/utilities/tests/test_auto_JointHistogram.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_JointHistogram.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_JointHistogram.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import JointHistogram
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_ShuffleVectorsModule.py b/nipype/interfaces/semtools/utilities/tests/test_auto_ShuffleVectorsModule.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_ShuffleVectorsModule.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_ShuffleVectorsModule.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import ShuffleVectorsModule
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_fcsv_to_hdf5.py b/nipype/interfaces/semtools/utilities/tests/test_auto_fcsv_to_hdf5.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_fcsv_to_hdf5.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_fcsv_to_hdf5.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import fcsv_to_hdf5
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_insertMidACPCpoint.py b/nipype/interfaces/semtools/utilities/tests/test_auto_insertMidACPCpoint.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_insertMidACPCpoint.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_insertMidACPCpoint.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import insertMidACPCpoint
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationAligner.py b/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationAligner.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationAligner.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationAligner.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import landmarksConstellationAligner
 
 
diff --git a/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationWeights.py b/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationWeights.py
--- a/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationWeights.py
+++ b/nipype/interfaces/semtools/utilities/tests/test_auto_landmarksConstellationWeights.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brains import landmarksConstellationWeights
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIexport.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIexport.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIexport.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIexport.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DTIexport
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIimport.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIimport.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIimport.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DTIimport.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DTIimport
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIJointRicianLMMSEFilter.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIJointRicianLMMSEFilter.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIJointRicianLMMSEFilter.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIJointRicianLMMSEFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DWIJointRicianLMMSEFilter
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIRicianLMMSEFilter.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIRicianLMMSEFilter.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIRicianLMMSEFilter.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIRicianLMMSEFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DWIRicianLMMSEFilter
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIToDTIEstimation.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIToDTIEstimation.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIToDTIEstimation.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DWIToDTIEstimation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DWIToDTIEstimation
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionTensorScalarMeasurements.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionTensorScalarMeasurements.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionTensorScalarMeasurements.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionTensorScalarMeasurements.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DiffusionTensorScalarMeasurements
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionWeightedVolumeMasking.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionWeightedVolumeMasking.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionWeightedVolumeMasking.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_DiffusionWeightedVolumeMasking.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import DiffusionWeightedVolumeMasking
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_ResampleDTIVolume.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_ResampleDTIVolume.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_ResampleDTIVolume.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_ResampleDTIVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import ResampleDTIVolume
 
 
diff --git a/nipype/interfaces/slicer/diffusion/tests/test_auto_TractographyLabelMapSeeding.py b/nipype/interfaces/slicer/diffusion/tests/test_auto_TractographyLabelMapSeeding.py
--- a/nipype/interfaces/slicer/diffusion/tests/test_auto_TractographyLabelMapSeeding.py
+++ b/nipype/interfaces/slicer/diffusion/tests/test_auto_TractographyLabelMapSeeding.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..diffusion import TractographyLabelMapSeeding
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_AddScalarVolumes.py b/nipype/interfaces/slicer/filtering/tests/test_auto_AddScalarVolumes.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_AddScalarVolumes.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_AddScalarVolumes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..arithmetic import AddScalarVolumes
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_CastScalarVolume.py b/nipype/interfaces/slicer/filtering/tests/test_auto_CastScalarVolume.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_CastScalarVolume.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_CastScalarVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..arithmetic import CastScalarVolume
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_CheckerBoardFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_CheckerBoardFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_CheckerBoardFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_CheckerBoardFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..checkerboardfilter import CheckerBoardFilter
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_CurvatureAnisotropicDiffusion.py b/nipype/interfaces/slicer/filtering/tests/test_auto_CurvatureAnisotropicDiffusion.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_CurvatureAnisotropicDiffusion.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_CurvatureAnisotropicDiffusion.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import CurvatureAnisotropicDiffusion
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_ExtractSkeleton.py b/nipype/interfaces/slicer/filtering/tests/test_auto_ExtractSkeleton.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_ExtractSkeleton.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_ExtractSkeleton.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..extractskeleton import ExtractSkeleton
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_GaussianBlurImageFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_GaussianBlurImageFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_GaussianBlurImageFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_GaussianBlurImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import GaussianBlurImageFilter
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_GradientAnisotropicDiffusion.py b/nipype/interfaces/slicer/filtering/tests/test_auto_GradientAnisotropicDiffusion.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_GradientAnisotropicDiffusion.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_GradientAnisotropicDiffusion.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import GradientAnisotropicDiffusion
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleFillHoleImageFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleFillHoleImageFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleFillHoleImageFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleFillHoleImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..morphology import GrayscaleFillHoleImageFilter
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleGrindPeakImageFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleGrindPeakImageFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleGrindPeakImageFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_GrayscaleGrindPeakImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..morphology import GrayscaleGrindPeakImageFilter
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_HistogramMatching.py b/nipype/interfaces/slicer/filtering/tests/test_auto_HistogramMatching.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_HistogramMatching.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_HistogramMatching.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..histogrammatching import HistogramMatching
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_ImageLabelCombine.py b/nipype/interfaces/slicer/filtering/tests/test_auto_ImageLabelCombine.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_ImageLabelCombine.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_ImageLabelCombine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..imagelabelcombine import ImageLabelCombine
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_MaskScalarVolume.py b/nipype/interfaces/slicer/filtering/tests/test_auto_MaskScalarVolume.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_MaskScalarVolume.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_MaskScalarVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..arithmetic import MaskScalarVolume
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_MedianImageFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_MedianImageFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_MedianImageFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_MedianImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import MedianImageFilter
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_MultiplyScalarVolumes.py b/nipype/interfaces/slicer/filtering/tests/test_auto_MultiplyScalarVolumes.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_MultiplyScalarVolumes.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_MultiplyScalarVolumes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..arithmetic import MultiplyScalarVolumes
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_N4ITKBiasFieldCorrection.py b/nipype/interfaces/slicer/filtering/tests/test_auto_N4ITKBiasFieldCorrection.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_N4ITKBiasFieldCorrection.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_N4ITKBiasFieldCorrection.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..n4itkbiasfieldcorrection import N4ITKBiasFieldCorrection
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_ResampleScalarVectorDWIVolume.py b/nipype/interfaces/slicer/filtering/tests/test_auto_ResampleScalarVectorDWIVolume.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_ResampleScalarVectorDWIVolume.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_ResampleScalarVectorDWIVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..resamplescalarvectordwivolume import ResampleScalarVectorDWIVolume
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_SubtractScalarVolumes.py b/nipype/interfaces/slicer/filtering/tests/test_auto_SubtractScalarVolumes.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_SubtractScalarVolumes.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_SubtractScalarVolumes.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..arithmetic import SubtractScalarVolumes
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_ThresholdScalarVolume.py b/nipype/interfaces/slicer/filtering/tests/test_auto_ThresholdScalarVolume.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_ThresholdScalarVolume.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_ThresholdScalarVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..thresholdscalarvolume import ThresholdScalarVolume
 
 
diff --git a/nipype/interfaces/slicer/filtering/tests/test_auto_VotingBinaryHoleFillingImageFilter.py b/nipype/interfaces/slicer/filtering/tests/test_auto_VotingBinaryHoleFillingImageFilter.py
--- a/nipype/interfaces/slicer/filtering/tests/test_auto_VotingBinaryHoleFillingImageFilter.py
+++ b/nipype/interfaces/slicer/filtering/tests/test_auto_VotingBinaryHoleFillingImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..votingbinaryholefillingimagefilter import VotingBinaryHoleFillingImageFilter
 
 
diff --git a/nipype/interfaces/slicer/legacy/diffusion/tests/test_auto_DWIUnbiasedNonLocalMeansFilter.py b/nipype/interfaces/slicer/legacy/diffusion/tests/test_auto_DWIUnbiasedNonLocalMeansFilter.py
--- a/nipype/interfaces/slicer/legacy/diffusion/tests/test_auto_DWIUnbiasedNonLocalMeansFilter.py
+++ b/nipype/interfaces/slicer/legacy/diffusion/tests/test_auto_DWIUnbiasedNonLocalMeansFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..denoising import DWIUnbiasedNonLocalMeansFilter
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_AffineRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_AffineRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_AffineRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_AffineRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import AffineRegistration
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineDeformableRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineDeformableRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineDeformableRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineDeformableRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import BSplineDeformableRegistration
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineToDeformationField.py b/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineToDeformationField.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineToDeformationField.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_BSplineToDeformationField.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..converters import BSplineToDeformationField
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_ExpertAutomatedRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_ExpertAutomatedRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_ExpertAutomatedRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_ExpertAutomatedRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import ExpertAutomatedRegistration
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_LinearRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_LinearRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_LinearRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_LinearRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import LinearRegistration
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_MultiResolutionAffineRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_MultiResolutionAffineRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_MultiResolutionAffineRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_MultiResolutionAffineRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import MultiResolutionAffineRegistration
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdImageFilter.py b/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdImageFilter.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdImageFilter.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdImageFilter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..filtering import OtsuThresholdImageFilter
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdSegmentation.py b/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdSegmentation.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdSegmentation.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_OtsuThresholdSegmentation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..segmentation import OtsuThresholdSegmentation
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_ResampleScalarVolume.py b/nipype/interfaces/slicer/legacy/tests/test_auto_ResampleScalarVolume.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_ResampleScalarVolume.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_ResampleScalarVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..filtering import ResampleScalarVolume
 
 
diff --git a/nipype/interfaces/slicer/legacy/tests/test_auto_RigidRegistration.py b/nipype/interfaces/slicer/legacy/tests/test_auto_RigidRegistration.py
--- a/nipype/interfaces/slicer/legacy/tests/test_auto_RigidRegistration.py
+++ b/nipype/interfaces/slicer/legacy/tests/test_auto_RigidRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..registration import RigidRegistration
 
 
diff --git a/nipype/interfaces/slicer/quantification/tests/test_auto_IntensityDifferenceMetric.py b/nipype/interfaces/slicer/quantification/tests/test_auto_IntensityDifferenceMetric.py
--- a/nipype/interfaces/slicer/quantification/tests/test_auto_IntensityDifferenceMetric.py
+++ b/nipype/interfaces/slicer/quantification/tests/test_auto_IntensityDifferenceMetric.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..changequantification import IntensityDifferenceMetric
 
 
diff --git a/nipype/interfaces/slicer/quantification/tests/test_auto_PETStandardUptakeValueComputation.py b/nipype/interfaces/slicer/quantification/tests/test_auto_PETStandardUptakeValueComputation.py
--- a/nipype/interfaces/slicer/quantification/tests/test_auto_PETStandardUptakeValueComputation.py
+++ b/nipype/interfaces/slicer/quantification/tests/test_auto_PETStandardUptakeValueComputation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..petstandarduptakevaluecomputation import PETStandardUptakeValueComputation
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_ACPCTransform.py b/nipype/interfaces/slicer/registration/tests/test_auto_ACPCTransform.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_ACPCTransform.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_ACPCTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import ACPCTransform
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSDemonWarp.py b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSDemonWarp.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSDemonWarp.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSDemonWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSDemonWarp
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSFit.py b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSFit.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSFit.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSFit.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsfit import BRAINSFit
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSResample.py b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSResample.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSResample.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_BRAINSResample.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..brainsresample import BRAINSResample
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_FiducialRegistration.py b/nipype/interfaces/slicer/registration/tests/test_auto_FiducialRegistration.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_FiducialRegistration.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_FiducialRegistration.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import FiducialRegistration
 
 
diff --git a/nipype/interfaces/slicer/registration/tests/test_auto_VBRAINSDemonWarp.py b/nipype/interfaces/slicer/registration/tests/test_auto_VBRAINSDemonWarp.py
--- a/nipype/interfaces/slicer/registration/tests/test_auto_VBRAINSDemonWarp.py
+++ b/nipype/interfaces/slicer/registration/tests/test_auto_VBRAINSDemonWarp.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import VBRAINSDemonWarp
 
 
diff --git a/nipype/interfaces/slicer/segmentation/tests/test_auto_BRAINSROIAuto.py b/nipype/interfaces/slicer/segmentation/tests/test_auto_BRAINSROIAuto.py
--- a/nipype/interfaces/slicer/segmentation/tests/test_auto_BRAINSROIAuto.py
+++ b/nipype/interfaces/slicer/segmentation/tests/test_auto_BRAINSROIAuto.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import BRAINSROIAuto
 
 
diff --git a/nipype/interfaces/slicer/segmentation/tests/test_auto_EMSegmentCommandLine.py b/nipype/interfaces/slicer/segmentation/tests/test_auto_EMSegmentCommandLine.py
--- a/nipype/interfaces/slicer/segmentation/tests/test_auto_EMSegmentCommandLine.py
+++ b/nipype/interfaces/slicer/segmentation/tests/test_auto_EMSegmentCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import EMSegmentCommandLine
 
 
diff --git a/nipype/interfaces/slicer/segmentation/tests/test_auto_RobustStatisticsSegmenter.py b/nipype/interfaces/slicer/segmentation/tests/test_auto_RobustStatisticsSegmenter.py
--- a/nipype/interfaces/slicer/segmentation/tests/test_auto_RobustStatisticsSegmenter.py
+++ b/nipype/interfaces/slicer/segmentation/tests/test_auto_RobustStatisticsSegmenter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..specialized import RobustStatisticsSegmenter
 
 
diff --git a/nipype/interfaces/slicer/segmentation/tests/test_auto_SimpleRegionGrowingSegmentation.py b/nipype/interfaces/slicer/segmentation/tests/test_auto_SimpleRegionGrowingSegmentation.py
--- a/nipype/interfaces/slicer/segmentation/tests/test_auto_SimpleRegionGrowingSegmentation.py
+++ b/nipype/interfaces/slicer/segmentation/tests/test_auto_SimpleRegionGrowingSegmentation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..simpleregiongrowingsegmentation import SimpleRegionGrowingSegmentation
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_DicomToNrrdConverter.py b/nipype/interfaces/slicer/tests/test_auto_DicomToNrrdConverter.py
--- a/nipype/interfaces/slicer/tests/test_auto_DicomToNrrdConverter.py
+++ b/nipype/interfaces/slicer/tests/test_auto_DicomToNrrdConverter.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..converters import DicomToNrrdConverter
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_EMSegmentTransformToNewFormat.py b/nipype/interfaces/slicer/tests/test_auto_EMSegmentTransformToNewFormat.py
--- a/nipype/interfaces/slicer/tests/test_auto_EMSegmentTransformToNewFormat.py
+++ b/nipype/interfaces/slicer/tests/test_auto_EMSegmentTransformToNewFormat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utilities import EMSegmentTransformToNewFormat
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_GrayscaleModelMaker.py b/nipype/interfaces/slicer/tests/test_auto_GrayscaleModelMaker.py
--- a/nipype/interfaces/slicer/tests/test_auto_GrayscaleModelMaker.py
+++ b/nipype/interfaces/slicer/tests/test_auto_GrayscaleModelMaker.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import GrayscaleModelMaker
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_LabelMapSmoothing.py b/nipype/interfaces/slicer/tests/test_auto_LabelMapSmoothing.py
--- a/nipype/interfaces/slicer/tests/test_auto_LabelMapSmoothing.py
+++ b/nipype/interfaces/slicer/tests/test_auto_LabelMapSmoothing.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import LabelMapSmoothing
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_MergeModels.py b/nipype/interfaces/slicer/tests/test_auto_MergeModels.py
--- a/nipype/interfaces/slicer/tests/test_auto_MergeModels.py
+++ b/nipype/interfaces/slicer/tests/test_auto_MergeModels.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import MergeModels
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_ModelMaker.py b/nipype/interfaces/slicer/tests/test_auto_ModelMaker.py
--- a/nipype/interfaces/slicer/tests/test_auto_ModelMaker.py
+++ b/nipype/interfaces/slicer/tests/test_auto_ModelMaker.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import ModelMaker
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_ModelToLabelMap.py b/nipype/interfaces/slicer/tests/test_auto_ModelToLabelMap.py
--- a/nipype/interfaces/slicer/tests/test_auto_ModelToLabelMap.py
+++ b/nipype/interfaces/slicer/tests/test_auto_ModelToLabelMap.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import ModelToLabelMap
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_OrientScalarVolume.py b/nipype/interfaces/slicer/tests/test_auto_OrientScalarVolume.py
--- a/nipype/interfaces/slicer/tests/test_auto_OrientScalarVolume.py
+++ b/nipype/interfaces/slicer/tests/test_auto_OrientScalarVolume.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..converters import OrientScalarVolume
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_ProbeVolumeWithModel.py b/nipype/interfaces/slicer/tests/test_auto_ProbeVolumeWithModel.py
--- a/nipype/interfaces/slicer/tests/test_auto_ProbeVolumeWithModel.py
+++ b/nipype/interfaces/slicer/tests/test_auto_ProbeVolumeWithModel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..surface import ProbeVolumeWithModel
 
 
diff --git a/nipype/interfaces/slicer/tests/test_auto_SlicerCommandLine.py b/nipype/interfaces/slicer/tests/test_auto_SlicerCommandLine.py
--- a/nipype/interfaces/slicer/tests/test_auto_SlicerCommandLine.py
+++ b/nipype/interfaces/slicer/tests/test_auto_SlicerCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import SlicerCommandLine
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Analyze2nii.py b/nipype/interfaces/spm/tests/test_auto_Analyze2nii.py
--- a/nipype/interfaces/spm/tests/test_auto_Analyze2nii.py
+++ b/nipype/interfaces/spm/tests/test_auto_Analyze2nii.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Analyze2nii
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_ApplyDeformations.py b/nipype/interfaces/spm/tests/test_auto_ApplyDeformations.py
--- a/nipype/interfaces/spm/tests/test_auto_ApplyDeformations.py
+++ b/nipype/interfaces/spm/tests/test_auto_ApplyDeformations.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import ApplyDeformations
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_ApplyInverseDeformation.py b/nipype/interfaces/spm/tests/test_auto_ApplyInverseDeformation.py
--- a/nipype/interfaces/spm/tests/test_auto_ApplyInverseDeformation.py
+++ b/nipype/interfaces/spm/tests/test_auto_ApplyInverseDeformation.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ApplyInverseDeformation
 
 
@@ -6,10 +7,10 @@ def test_ApplyInverseDeformation_inputs():
     input_map = dict(bounding_box=dict(field='comp{1}.inv.comp{1}.sn2def.bb',
     ),
     deformation=dict(field='comp{1}.inv.comp{1}.sn2def.matname',
-    xor=[u'deformation_field'],
+    xor=['deformation_field'],
     ),
     deformation_field=dict(field='comp{1}.inv.comp{1}.def',
-    xor=[u'deformation'],
+    xor=['deformation'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/spm/tests/test_auto_ApplyTransform.py b/nipype/interfaces/spm/tests/test_auto_ApplyTransform.py
--- a/nipype/interfaces/spm/tests/test_auto_ApplyTransform.py
+++ b/nipype/interfaces/spm/tests/test_auto_ApplyTransform.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ApplyTransform
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_CalcCoregAffine.py b/nipype/interfaces/spm/tests/test_auto_CalcCoregAffine.py
--- a/nipype/interfaces/spm/tests/test_auto_CalcCoregAffine.py
+++ b/nipype/interfaces/spm/tests/test_auto_CalcCoregAffine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import CalcCoregAffine
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Coregister.py b/nipype/interfaces/spm/tests/test_auto_Coregister.py
--- a/nipype/interfaces/spm/tests/test_auto_Coregister.py
+++ b/nipype/interfaces/spm/tests/test_auto_Coregister.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Coregister
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_CreateWarped.py b/nipype/interfaces/spm/tests/test_auto_CreateWarped.py
--- a/nipype/interfaces/spm/tests/test_auto_CreateWarped.py
+++ b/nipype/interfaces/spm/tests/test_auto_CreateWarped.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import CreateWarped
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_DARTEL.py b/nipype/interfaces/spm/tests/test_auto_DARTEL.py
--- a/nipype/interfaces/spm/tests/test_auto_DARTEL.py
+++ b/nipype/interfaces/spm/tests/test_auto_DARTEL.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import DARTEL
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_DARTELNorm2MNI.py b/nipype/interfaces/spm/tests/test_auto_DARTELNorm2MNI.py
--- a/nipype/interfaces/spm/tests/test_auto_DARTELNorm2MNI.py
+++ b/nipype/interfaces/spm/tests/test_auto_DARTELNorm2MNI.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import DARTELNorm2MNI
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_DicomImport.py b/nipype/interfaces/spm/tests/test_auto_DicomImport.py
--- a/nipype/interfaces/spm/tests/test_auto_DicomImport.py
+++ b/nipype/interfaces/spm/tests/test_auto_DicomImport.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import DicomImport
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_EstimateContrast.py b/nipype/interfaces/spm/tests/test_auto_EstimateContrast.py
--- a/nipype/interfaces/spm/tests/test_auto_EstimateContrast.py
+++ b/nipype/interfaces/spm/tests/test_auto_EstimateContrast.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import EstimateContrast
 
 
@@ -8,7 +9,7 @@ def test_EstimateContrast_inputs():
     ),
     contrasts=dict(mandatory=True,
     ),
-    group_contrast=dict(xor=[u'use_derivs'],
+    group_contrast=dict(xor=['use_derivs'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -24,7 +25,7 @@ def test_EstimateContrast_inputs():
     field='spmmat',
     mandatory=True,
     ),
-    use_derivs=dict(xor=[u'group_contrast'],
+    use_derivs=dict(xor=['group_contrast'],
     ),
     use_mcr=dict(),
     use_v8struct=dict(min_ver='8',
diff --git a/nipype/interfaces/spm/tests/test_auto_EstimateModel.py b/nipype/interfaces/spm/tests/test_auto_EstimateModel.py
--- a/nipype/interfaces/spm/tests/test_auto_EstimateModel.py
+++ b/nipype/interfaces/spm/tests/test_auto_EstimateModel.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import EstimateModel
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_FactorialDesign.py b/nipype/interfaces/spm/tests/test_auto_FactorialDesign.py
--- a/nipype/interfaces/spm/tests/test_auto_FactorialDesign.py
+++ b/nipype/interfaces/spm/tests/test_auto_FactorialDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import FactorialDesign
 
 
@@ -8,13 +9,13 @@ def test_FactorialDesign_inputs():
     explicit_mask_file=dict(field='masking.em',
     ),
     global_calc_mean=dict(field='globalc.g_mean',
-    xor=[u'global_calc_omit', u'global_calc_values'],
+    xor=['global_calc_omit', 'global_calc_values'],
     ),
     global_calc_omit=dict(field='globalc.g_omit',
-    xor=[u'global_calc_mean', u'global_calc_values'],
+    xor=['global_calc_mean', 'global_calc_values'],
     ),
     global_calc_values=dict(field='globalc.g_user.global_uval',
-    xor=[u'global_calc_mean', u'global_calc_omit'],
+    xor=['global_calc_mean', 'global_calc_omit'],
     ),
     global_normalization=dict(field='globalm.glonorm',
     ),
@@ -30,13 +31,13 @@ def test_FactorialDesign_inputs():
     spm_mat_dir=dict(field='dir',
     ),
     threshold_mask_absolute=dict(field='masking.tm.tma.athresh',
-    xor=[u'threshold_mask_none', u'threshold_mask_relative'],
+    xor=['threshold_mask_none', 'threshold_mask_relative'],
     ),
     threshold_mask_none=dict(field='masking.tm.tm_none',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_relative'],
+    xor=['threshold_mask_absolute', 'threshold_mask_relative'],
     ),
     threshold_mask_relative=dict(field='masking.tm.tmr.rthresh',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_none'],
+    xor=['threshold_mask_absolute', 'threshold_mask_none'],
     ),
     use_implicit_threshold=dict(field='masking.im',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_Level1Design.py b/nipype/interfaces/spm/tests/test_auto_Level1Design.py
--- a/nipype/interfaces/spm/tests/test_auto_Level1Design.py
+++ b/nipype/interfaces/spm/tests/test_auto_Level1Design.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Level1Design
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_MultipleRegressionDesign.py b/nipype/interfaces/spm/tests/test_auto_MultipleRegressionDesign.py
--- a/nipype/interfaces/spm/tests/test_auto_MultipleRegressionDesign.py
+++ b/nipype/interfaces/spm/tests/test_auto_MultipleRegressionDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import MultipleRegressionDesign
 
 
@@ -8,13 +9,13 @@ def test_MultipleRegressionDesign_inputs():
     explicit_mask_file=dict(field='masking.em',
     ),
     global_calc_mean=dict(field='globalc.g_mean',
-    xor=[u'global_calc_omit', u'global_calc_values'],
+    xor=['global_calc_omit', 'global_calc_values'],
     ),
     global_calc_omit=dict(field='globalc.g_omit',
-    xor=[u'global_calc_mean', u'global_calc_values'],
+    xor=['global_calc_mean', 'global_calc_values'],
     ),
     global_calc_values=dict(field='globalc.g_user.global_uval',
-    xor=[u'global_calc_mean', u'global_calc_omit'],
+    xor=['global_calc_mean', 'global_calc_omit'],
     ),
     global_normalization=dict(field='globalm.glonorm',
     ),
@@ -36,13 +37,13 @@ def test_MultipleRegressionDesign_inputs():
     spm_mat_dir=dict(field='dir',
     ),
     threshold_mask_absolute=dict(field='masking.tm.tma.athresh',
-    xor=[u'threshold_mask_none', u'threshold_mask_relative'],
+    xor=['threshold_mask_none', 'threshold_mask_relative'],
     ),
     threshold_mask_none=dict(field='masking.tm.tm_none',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_relative'],
+    xor=['threshold_mask_absolute', 'threshold_mask_relative'],
     ),
     threshold_mask_relative=dict(field='masking.tm.tmr.rthresh',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_none'],
+    xor=['threshold_mask_absolute', 'threshold_mask_none'],
     ),
     use_implicit_threshold=dict(field='masking.im',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_NewSegment.py b/nipype/interfaces/spm/tests/test_auto_NewSegment.py
--- a/nipype/interfaces/spm/tests/test_auto_NewSegment.py
+++ b/nipype/interfaces/spm/tests/test_auto_NewSegment.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import NewSegment
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Normalize.py b/nipype/interfaces/spm/tests/test_auto_Normalize.py
--- a/nipype/interfaces/spm/tests/test_auto_Normalize.py
+++ b/nipype/interfaces/spm/tests/test_auto_Normalize.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Normalize
 
 
@@ -28,13 +29,13 @@ def test_Normalize_inputs():
     parameter_file=dict(copyfile=False,
     field='subj.matname',
     mandatory=True,
-    xor=[u'source', u'template'],
+    xor=['source', 'template'],
     ),
     paths=dict(),
     source=dict(copyfile=True,
     field='subj.source',
     mandatory=True,
-    xor=[u'parameter_file'],
+    xor=['parameter_file'],
     ),
     source_image_smoothing=dict(field='eoptions.smosrc',
     ),
@@ -44,7 +45,7 @@ def test_Normalize_inputs():
     template=dict(copyfile=False,
     field='eoptions.template',
     mandatory=True,
-    xor=[u'parameter_file'],
+    xor=['parameter_file'],
     ),
     template_image_smoothing=dict(field='eoptions.smoref',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_Normalize12.py b/nipype/interfaces/spm/tests/test_auto_Normalize12.py
--- a/nipype/interfaces/spm/tests/test_auto_Normalize12.py
+++ b/nipype/interfaces/spm/tests/test_auto_Normalize12.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Normalize12
 
 
@@ -15,7 +16,7 @@ def test_Normalize12_inputs():
     deformation_file=dict(copyfile=False,
     field='subj.def',
     mandatory=True,
-    xor=[u'image_to_align', u'tpm'],
+    xor=['image_to_align', 'tpm'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -23,7 +24,7 @@ def test_Normalize12_inputs():
     image_to_align=dict(copyfile=True,
     field='subj.vol',
     mandatory=True,
-    xor=[u'deformation_file'],
+    xor=['deformation_file'],
     ),
     jobtype=dict(usedefault=True,
     ),
@@ -40,7 +41,7 @@ def test_Normalize12_inputs():
     ),
     tpm=dict(copyfile=False,
     field='eoptions.tpm',
-    xor=[u'deformation_file'],
+    xor=['deformation_file'],
     ),
     use_mcr=dict(),
     use_v8struct=dict(min_ver='8',
diff --git a/nipype/interfaces/spm/tests/test_auto_OneSampleTTestDesign.py b/nipype/interfaces/spm/tests/test_auto_OneSampleTTestDesign.py
--- a/nipype/interfaces/spm/tests/test_auto_OneSampleTTestDesign.py
+++ b/nipype/interfaces/spm/tests/test_auto_OneSampleTTestDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import OneSampleTTestDesign
 
 
@@ -8,13 +9,13 @@ def test_OneSampleTTestDesign_inputs():
     explicit_mask_file=dict(field='masking.em',
     ),
     global_calc_mean=dict(field='globalc.g_mean',
-    xor=[u'global_calc_omit', u'global_calc_values'],
+    xor=['global_calc_omit', 'global_calc_values'],
     ),
     global_calc_omit=dict(field='globalc.g_omit',
-    xor=[u'global_calc_mean', u'global_calc_values'],
+    xor=['global_calc_mean', 'global_calc_values'],
     ),
     global_calc_values=dict(field='globalc.g_user.global_uval',
-    xor=[u'global_calc_mean', u'global_calc_omit'],
+    xor=['global_calc_mean', 'global_calc_omit'],
     ),
     global_normalization=dict(field='globalm.glonorm',
     ),
@@ -33,13 +34,13 @@ def test_OneSampleTTestDesign_inputs():
     spm_mat_dir=dict(field='dir',
     ),
     threshold_mask_absolute=dict(field='masking.tm.tma.athresh',
-    xor=[u'threshold_mask_none', u'threshold_mask_relative'],
+    xor=['threshold_mask_none', 'threshold_mask_relative'],
     ),
     threshold_mask_none=dict(field='masking.tm.tm_none',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_relative'],
+    xor=['threshold_mask_absolute', 'threshold_mask_relative'],
     ),
     threshold_mask_relative=dict(field='masking.tm.tmr.rthresh',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_none'],
+    xor=['threshold_mask_absolute', 'threshold_mask_none'],
     ),
     use_implicit_threshold=dict(field='masking.im',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_PairedTTestDesign.py b/nipype/interfaces/spm/tests/test_auto_PairedTTestDesign.py
--- a/nipype/interfaces/spm/tests/test_auto_PairedTTestDesign.py
+++ b/nipype/interfaces/spm/tests/test_auto_PairedTTestDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import PairedTTestDesign
 
 
@@ -10,13 +11,13 @@ def test_PairedTTestDesign_inputs():
     explicit_mask_file=dict(field='masking.em',
     ),
     global_calc_mean=dict(field='globalc.g_mean',
-    xor=[u'global_calc_omit', u'global_calc_values'],
+    xor=['global_calc_omit', 'global_calc_values'],
     ),
     global_calc_omit=dict(field='globalc.g_omit',
-    xor=[u'global_calc_mean', u'global_calc_values'],
+    xor=['global_calc_mean', 'global_calc_values'],
     ),
     global_calc_values=dict(field='globalc.g_user.global_uval',
-    xor=[u'global_calc_mean', u'global_calc_omit'],
+    xor=['global_calc_mean', 'global_calc_omit'],
     ),
     global_normalization=dict(field='globalm.glonorm',
     ),
@@ -37,13 +38,13 @@ def test_PairedTTestDesign_inputs():
     spm_mat_dir=dict(field='dir',
     ),
     threshold_mask_absolute=dict(field='masking.tm.tma.athresh',
-    xor=[u'threshold_mask_none', u'threshold_mask_relative'],
+    xor=['threshold_mask_none', 'threshold_mask_relative'],
     ),
     threshold_mask_none=dict(field='masking.tm.tm_none',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_relative'],
+    xor=['threshold_mask_absolute', 'threshold_mask_relative'],
     ),
     threshold_mask_relative=dict(field='masking.tm.tmr.rthresh',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_none'],
+    xor=['threshold_mask_absolute', 'threshold_mask_none'],
     ),
     use_implicit_threshold=dict(field='masking.im',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_Realign.py b/nipype/interfaces/spm/tests/test_auto_Realign.py
--- a/nipype/interfaces/spm/tests/test_auto_Realign.py
+++ b/nipype/interfaces/spm/tests/test_auto_Realign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Realign
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Reslice.py b/nipype/interfaces/spm/tests/test_auto_Reslice.py
--- a/nipype/interfaces/spm/tests/test_auto_Reslice.py
+++ b/nipype/interfaces/spm/tests/test_auto_Reslice.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import Reslice
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_ResliceToReference.py b/nipype/interfaces/spm/tests/test_auto_ResliceToReference.py
--- a/nipype/interfaces/spm/tests/test_auto_ResliceToReference.py
+++ b/nipype/interfaces/spm/tests/test_auto_ResliceToReference.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..utils import ResliceToReference
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_SPMCommand.py b/nipype/interfaces/spm/tests/test_auto_SPMCommand.py
--- a/nipype/interfaces/spm/tests/test_auto_SPMCommand.py
+++ b/nipype/interfaces/spm/tests/test_auto_SPMCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import SPMCommand
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Segment.py b/nipype/interfaces/spm/tests/test_auto_Segment.py
--- a/nipype/interfaces/spm/tests/test_auto_Segment.py
+++ b/nipype/interfaces/spm/tests/test_auto_Segment.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Segment
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_SliceTiming.py b/nipype/interfaces/spm/tests/test_auto_SliceTiming.py
--- a/nipype/interfaces/spm/tests/test_auto_SliceTiming.py
+++ b/nipype/interfaces/spm/tests/test_auto_SliceTiming.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import SliceTiming
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Smooth.py b/nipype/interfaces/spm/tests/test_auto_Smooth.py
--- a/nipype/interfaces/spm/tests/test_auto_Smooth.py
+++ b/nipype/interfaces/spm/tests/test_auto_Smooth.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import Smooth
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_Threshold.py b/nipype/interfaces/spm/tests/test_auto_Threshold.py
--- a/nipype/interfaces/spm/tests/test_auto_Threshold.py
+++ b/nipype/interfaces/spm/tests/test_auto_Threshold.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import Threshold
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_ThresholdStatistics.py b/nipype/interfaces/spm/tests/test_auto_ThresholdStatistics.py
--- a/nipype/interfaces/spm/tests/test_auto_ThresholdStatistics.py
+++ b/nipype/interfaces/spm/tests/test_auto_ThresholdStatistics.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import ThresholdStatistics
 
 
diff --git a/nipype/interfaces/spm/tests/test_auto_TwoSampleTTestDesign.py b/nipype/interfaces/spm/tests/test_auto_TwoSampleTTestDesign.py
--- a/nipype/interfaces/spm/tests/test_auto_TwoSampleTTestDesign.py
+++ b/nipype/interfaces/spm/tests/test_auto_TwoSampleTTestDesign.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..model import TwoSampleTTestDesign
 
 
@@ -10,13 +11,13 @@ def test_TwoSampleTTestDesign_inputs():
     explicit_mask_file=dict(field='masking.em',
     ),
     global_calc_mean=dict(field='globalc.g_mean',
-    xor=[u'global_calc_omit', u'global_calc_values'],
+    xor=['global_calc_omit', 'global_calc_values'],
     ),
     global_calc_omit=dict(field='globalc.g_omit',
-    xor=[u'global_calc_mean', u'global_calc_values'],
+    xor=['global_calc_mean', 'global_calc_values'],
     ),
     global_calc_values=dict(field='globalc.g_user.global_uval',
-    xor=[u'global_calc_mean', u'global_calc_omit'],
+    xor=['global_calc_mean', 'global_calc_omit'],
     ),
     global_normalization=dict(field='globalm.glonorm',
     ),
@@ -38,13 +39,13 @@ def test_TwoSampleTTestDesign_inputs():
     spm_mat_dir=dict(field='dir',
     ),
     threshold_mask_absolute=dict(field='masking.tm.tma.athresh',
-    xor=[u'threshold_mask_none', u'threshold_mask_relative'],
+    xor=['threshold_mask_none', 'threshold_mask_relative'],
     ),
     threshold_mask_none=dict(field='masking.tm.tm_none',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_relative'],
+    xor=['threshold_mask_absolute', 'threshold_mask_relative'],
     ),
     threshold_mask_relative=dict(field='masking.tm.tmr.rthresh',
-    xor=[u'threshold_mask_absolute', u'threshold_mask_none'],
+    xor=['threshold_mask_absolute', 'threshold_mask_none'],
     ),
     unequal_variance=dict(field='des.t2.variance',
     ),
diff --git a/nipype/interfaces/spm/tests/test_auto_VBMSegment.py b/nipype/interfaces/spm/tests/test_auto_VBMSegment.py
--- a/nipype/interfaces/spm/tests/test_auto_VBMSegment.py
+++ b/nipype/interfaces/spm/tests/test_auto_VBMSegment.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..preprocess import VBMSegment
 
 
diff --git a/nipype/interfaces/tests/test_auto_BaseInterface.py b/nipype/interfaces/tests/test_auto_BaseInterface.py
--- a/nipype/interfaces/tests/test_auto_BaseInterface.py
+++ b/nipype/interfaces/tests/test_auto_BaseInterface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import BaseInterface
 
 
diff --git a/nipype/interfaces/tests/test_auto_Bru2.py b/nipype/interfaces/tests/test_auto_Bru2.py
--- a/nipype/interfaces/tests/test_auto_Bru2.py
+++ b/nipype/interfaces/tests/test_auto_Bru2.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..bru2nii import Bru2
 
 
diff --git a/nipype/interfaces/tests/test_auto_C3dAffineTool.py b/nipype/interfaces/tests/test_auto_C3dAffineTool.py
--- a/nipype/interfaces/tests/test_auto_C3dAffineTool.py
+++ b/nipype/interfaces/tests/test_auto_C3dAffineTool.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..c3 import C3dAffineTool
 
 
diff --git a/nipype/interfaces/tests/test_auto_CommandLine.py b/nipype/interfaces/tests/test_auto_CommandLine.py
--- a/nipype/interfaces/tests/test_auto_CommandLine.py
+++ b/nipype/interfaces/tests/test_auto_CommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import CommandLine
 
 
diff --git a/nipype/interfaces/tests/test_auto_CopyMeta.py b/nipype/interfaces/tests/test_auto_CopyMeta.py
--- a/nipype/interfaces/tests/test_auto_CopyMeta.py
+++ b/nipype/interfaces/tests/test_auto_CopyMeta.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import CopyMeta
 
 
diff --git a/nipype/interfaces/tests/test_auto_DataFinder.py b/nipype/interfaces/tests/test_auto_DataFinder.py
--- a/nipype/interfaces/tests/test_auto_DataFinder.py
+++ b/nipype/interfaces/tests/test_auto_DataFinder.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import DataFinder
 
 
diff --git a/nipype/interfaces/tests/test_auto_DataGrabber.py b/nipype/interfaces/tests/test_auto_DataGrabber.py
--- a/nipype/interfaces/tests/test_auto_DataGrabber.py
+++ b/nipype/interfaces/tests/test_auto_DataGrabber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import DataGrabber
 
 
diff --git a/nipype/interfaces/tests/test_auto_DataSink.py b/nipype/interfaces/tests/test_auto_DataSink.py
--- a/nipype/interfaces/tests/test_auto_DataSink.py
+++ b/nipype/interfaces/tests/test_auto_DataSink.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import DataSink
 
 
diff --git a/nipype/interfaces/tests/test_auto_Dcm2nii.py b/nipype/interfaces/tests/test_auto_Dcm2nii.py
--- a/nipype/interfaces/tests/test_auto_Dcm2nii.py
+++ b/nipype/interfaces/tests/test_auto_Dcm2nii.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcm2nii import Dcm2nii
 
 
@@ -52,7 +53,7 @@ def test_Dcm2nii_inputs():
     source_dir=dict(argstr='%s',
     mandatory=True,
     position=-1,
-    xor=[u'source_names'],
+    xor=['source_names'],
     ),
     source_in_filename=dict(argstr='-f',
     usedefault=True,
@@ -61,10 +62,10 @@ def test_Dcm2nii_inputs():
     copyfile=False,
     mandatory=True,
     position=-1,
-    xor=[u'source_dir'],
+    xor=['source_dir'],
     ),
     spm_analyze=dict(argstr='-s',
-    xor=[u'nii_output'],
+    xor=['nii_output'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/tests/test_auto_Dcm2niix.py b/nipype/interfaces/tests/test_auto_Dcm2niix.py
--- a/nipype/interfaces/tests/test_auto_Dcm2niix.py
+++ b/nipype/interfaces/tests/test_auto_Dcm2niix.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcm2nii import Dcm2niix
 
 
@@ -38,13 +39,13 @@ def test_Dcm2niix_inputs():
     source_dir=dict(argstr='%s',
     mandatory=True,
     position=-1,
-    xor=[u'source_names'],
+    xor=['source_names'],
     ),
     source_names=dict(argstr='%s',
     copyfile=False,
     mandatory=True,
     position=-1,
-    xor=[u'source_dir'],
+    xor=['source_dir'],
     ),
     terminal_output=dict(nohash=True,
     ),
diff --git a/nipype/interfaces/tests/test_auto_DcmStack.py b/nipype/interfaces/tests/test_auto_DcmStack.py
--- a/nipype/interfaces/tests/test_auto_DcmStack.py
+++ b/nipype/interfaces/tests/test_auto_DcmStack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import DcmStack
 
 
diff --git a/nipype/interfaces/tests/test_auto_FreeSurferSource.py b/nipype/interfaces/tests/test_auto_FreeSurferSource.py
--- a/nipype/interfaces/tests/test_auto_FreeSurferSource.py
+++ b/nipype/interfaces/tests/test_auto_FreeSurferSource.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import FreeSurferSource
 
 
diff --git a/nipype/interfaces/tests/test_auto_GroupAndStack.py b/nipype/interfaces/tests/test_auto_GroupAndStack.py
--- a/nipype/interfaces/tests/test_auto_GroupAndStack.py
+++ b/nipype/interfaces/tests/test_auto_GroupAndStack.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import GroupAndStack
 
 
diff --git a/nipype/interfaces/tests/test_auto_IOBase.py b/nipype/interfaces/tests/test_auto_IOBase.py
--- a/nipype/interfaces/tests/test_auto_IOBase.py
+++ b/nipype/interfaces/tests/test_auto_IOBase.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import IOBase
 
 
diff --git a/nipype/interfaces/tests/test_auto_JSONFileGrabber.py b/nipype/interfaces/tests/test_auto_JSONFileGrabber.py
--- a/nipype/interfaces/tests/test_auto_JSONFileGrabber.py
+++ b/nipype/interfaces/tests/test_auto_JSONFileGrabber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import JSONFileGrabber
 
 
diff --git a/nipype/interfaces/tests/test_auto_JSONFileSink.py b/nipype/interfaces/tests/test_auto_JSONFileSink.py
--- a/nipype/interfaces/tests/test_auto_JSONFileSink.py
+++ b/nipype/interfaces/tests/test_auto_JSONFileSink.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import JSONFileSink
 
 
diff --git a/nipype/interfaces/tests/test_auto_LookupMeta.py b/nipype/interfaces/tests/test_auto_LookupMeta.py
--- a/nipype/interfaces/tests/test_auto_LookupMeta.py
+++ b/nipype/interfaces/tests/test_auto_LookupMeta.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import LookupMeta
 
 
diff --git a/nipype/interfaces/tests/test_auto_MatlabCommand.py b/nipype/interfaces/tests/test_auto_MatlabCommand.py
--- a/nipype/interfaces/tests/test_auto_MatlabCommand.py
+++ b/nipype/interfaces/tests/test_auto_MatlabCommand.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..matlab import MatlabCommand
 
 
@@ -40,7 +41,7 @@ def test_MatlabCommand_inputs():
     terminal_output=dict(nohash=True,
     ),
     uses_mcr=dict(nohash=True,
-    xor=[u'nodesktop', u'nosplash', u'single_comp_thread'],
+    xor=['nodesktop', 'nosplash', 'single_comp_thread'],
     ),
     )
     inputs = MatlabCommand.input_spec()
diff --git a/nipype/interfaces/tests/test_auto_MergeNifti.py b/nipype/interfaces/tests/test_auto_MergeNifti.py
--- a/nipype/interfaces/tests/test_auto_MergeNifti.py
+++ b/nipype/interfaces/tests/test_auto_MergeNifti.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import MergeNifti
 
 
diff --git a/nipype/interfaces/tests/test_auto_MeshFix.py b/nipype/interfaces/tests/test_auto_MeshFix.py
--- a/nipype/interfaces/tests/test_auto_MeshFix.py
+++ b/nipype/interfaces/tests/test_auto_MeshFix.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..meshfix import MeshFix
 
 
@@ -25,17 +26,17 @@ def test_MeshFix_inputs():
     epsilon_angle=dict(argstr='-a %f',
     ),
     finetuning_distance=dict(argstr='%f',
-    requires=[u'finetuning_substeps'],
+    requires=['finetuning_substeps'],
     ),
     finetuning_inwards=dict(argstr='--fineTuneIn ',
-    requires=[u'finetuning_distance', u'finetuning_substeps'],
+    requires=['finetuning_distance', 'finetuning_substeps'],
     ),
     finetuning_outwards=dict(argstr='--fineTuneIn ',
-    requires=[u'finetuning_distance', u'finetuning_substeps'],
-    xor=[u'finetuning_inwards'],
+    requires=['finetuning_distance', 'finetuning_substeps'],
+    xor=['finetuning_inwards'],
     ),
     finetuning_substeps=dict(argstr='%d',
-    requires=[u'finetuning_distance'],
+    requires=['finetuning_distance'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -48,10 +49,10 @@ def test_MeshFix_inputs():
     position=2,
     ),
     join_closest_components=dict(argstr='-jc',
-    xor=[u'join_closest_components'],
+    xor=['join_closest_components'],
     ),
     join_overlapping_largest_components=dict(argstr='-j',
-    xor=[u'join_closest_components'],
+    xor=['join_closest_components'],
     ),
     laplacian_smoothing_steps=dict(argstr='--smooth %d',
     ),
@@ -67,23 +68,23 @@ def test_MeshFix_inputs():
     remove_handles=dict(argstr='--remove-handles',
     ),
     save_as_freesurfer_mesh=dict(argstr='--fsmesh',
-    xor=[u'save_as_vrml', u'save_as_stl'],
+    xor=['save_as_vrml', 'save_as_stl'],
     ),
     save_as_stl=dict(argstr='--stl',
-    xor=[u'save_as_vmrl', u'save_as_freesurfer_mesh'],
+    xor=['save_as_vmrl', 'save_as_freesurfer_mesh'],
     ),
     save_as_vmrl=dict(argstr='--wrl',
-    xor=[u'save_as_stl', u'save_as_freesurfer_mesh'],
+    xor=['save_as_stl', 'save_as_freesurfer_mesh'],
     ),
     set_intersections_to_one=dict(argstr='--intersect',
     ),
     terminal_output=dict(nohash=True,
     ),
     uniform_remeshing_steps=dict(argstr='-u %d',
-    requires=[u'uniform_remeshing_vertices'],
+    requires=['uniform_remeshing_vertices'],
     ),
     uniform_remeshing_vertices=dict(argstr='--vertices %d',
-    requires=[u'uniform_remeshing_steps'],
+    requires=['uniform_remeshing_steps'],
     ),
     x_shift=dict(argstr='--smooth %d',
     ),
diff --git a/nipype/interfaces/tests/test_auto_MpiCommandLine.py b/nipype/interfaces/tests/test_auto_MpiCommandLine.py
--- a/nipype/interfaces/tests/test_auto_MpiCommandLine.py
+++ b/nipype/interfaces/tests/test_auto_MpiCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import MpiCommandLine
 
 
diff --git a/nipype/interfaces/tests/test_auto_MySQLSink.py b/nipype/interfaces/tests/test_auto_MySQLSink.py
--- a/nipype/interfaces/tests/test_auto_MySQLSink.py
+++ b/nipype/interfaces/tests/test_auto_MySQLSink.py
@@ -1,17 +1,18 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import MySQLSink
 
 
 def test_MySQLSink_inputs():
     input_map = dict(config=dict(mandatory=True,
-    xor=[u'host'],
+    xor=['host'],
     ),
     database_name=dict(mandatory=True,
     ),
     host=dict(mandatory=True,
-    requires=[u'username', u'password'],
+    requires=['username', 'password'],
     usedefault=True,
-    xor=[u'config'],
+    xor=['config'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
diff --git a/nipype/interfaces/tests/test_auto_NiftiGeneratorBase.py b/nipype/interfaces/tests/test_auto_NiftiGeneratorBase.py
--- a/nipype/interfaces/tests/test_auto_NiftiGeneratorBase.py
+++ b/nipype/interfaces/tests/test_auto_NiftiGeneratorBase.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import NiftiGeneratorBase
 
 
diff --git a/nipype/interfaces/tests/test_auto_PETPVC.py b/nipype/interfaces/tests/test_auto_PETPVC.py
--- a/nipype/interfaces/tests/test_auto_PETPVC.py
+++ b/nipype/interfaces/tests/test_auto_PETPVC.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..petpvc import PETPVC
 
 
diff --git a/nipype/interfaces/tests/test_auto_S3DataGrabber.py b/nipype/interfaces/tests/test_auto_S3DataGrabber.py
--- a/nipype/interfaces/tests/test_auto_S3DataGrabber.py
+++ b/nipype/interfaces/tests/test_auto_S3DataGrabber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import S3DataGrabber
 
 
diff --git a/nipype/interfaces/tests/test_auto_SEMLikeCommandLine.py b/nipype/interfaces/tests/test_auto_SEMLikeCommandLine.py
--- a/nipype/interfaces/tests/test_auto_SEMLikeCommandLine.py
+++ b/nipype/interfaces/tests/test_auto_SEMLikeCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import SEMLikeCommandLine
 
 
diff --git a/nipype/interfaces/tests/test_auto_SQLiteSink.py b/nipype/interfaces/tests/test_auto_SQLiteSink.py
--- a/nipype/interfaces/tests/test_auto_SQLiteSink.py
+++ b/nipype/interfaces/tests/test_auto_SQLiteSink.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import SQLiteSink
 
 
diff --git a/nipype/interfaces/tests/test_auto_SSHDataGrabber.py b/nipype/interfaces/tests/test_auto_SSHDataGrabber.py
--- a/nipype/interfaces/tests/test_auto_SSHDataGrabber.py
+++ b/nipype/interfaces/tests/test_auto_SSHDataGrabber.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import SSHDataGrabber
 
 
diff --git a/nipype/interfaces/tests/test_auto_SelectFiles.py b/nipype/interfaces/tests/test_auto_SelectFiles.py
--- a/nipype/interfaces/tests/test_auto_SelectFiles.py
+++ b/nipype/interfaces/tests/test_auto_SelectFiles.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import SelectFiles
 
 
diff --git a/nipype/interfaces/tests/test_auto_SignalExtraction.py b/nipype/interfaces/tests/test_auto_SignalExtraction.py
--- a/nipype/interfaces/tests/test_auto_SignalExtraction.py
+++ b/nipype/interfaces/tests/test_auto_SignalExtraction.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..nilearn import SignalExtraction
 
 
diff --git a/nipype/interfaces/tests/test_auto_SlicerCommandLine.py b/nipype/interfaces/tests/test_auto_SlicerCommandLine.py
--- a/nipype/interfaces/tests/test_auto_SlicerCommandLine.py
+++ b/nipype/interfaces/tests/test_auto_SlicerCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dynamic_slicer import SlicerCommandLine
 
 
diff --git a/nipype/interfaces/tests/test_auto_SplitNifti.py b/nipype/interfaces/tests/test_auto_SplitNifti.py
--- a/nipype/interfaces/tests/test_auto_SplitNifti.py
+++ b/nipype/interfaces/tests/test_auto_SplitNifti.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..dcmstack import SplitNifti
 
 
diff --git a/nipype/interfaces/tests/test_auto_StdOutCommandLine.py b/nipype/interfaces/tests/test_auto_StdOutCommandLine.py
--- a/nipype/interfaces/tests/test_auto_StdOutCommandLine.py
+++ b/nipype/interfaces/tests/test_auto_StdOutCommandLine.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import StdOutCommandLine
 
 
diff --git a/nipype/interfaces/tests/test_auto_XNATSink.py b/nipype/interfaces/tests/test_auto_XNATSink.py
--- a/nipype/interfaces/tests/test_auto_XNATSink.py
+++ b/nipype/interfaces/tests/test_auto_XNATSink.py
@@ -1,15 +1,16 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import XNATSink
 
 
 def test_XNATSink_inputs():
     input_map = dict(_outputs=dict(usedefault=True,
     ),
-    assessor_id=dict(xor=[u'reconstruction_id'],
+    assessor_id=dict(xor=['reconstruction_id'],
     ),
     cache_dir=dict(),
     config=dict(mandatory=True,
-    xor=[u'server'],
+    xor=['server'],
     ),
     experiment_id=dict(mandatory=True,
     ),
@@ -19,11 +20,11 @@ def test_XNATSink_inputs():
     project_id=dict(mandatory=True,
     ),
     pwd=dict(),
-    reconstruction_id=dict(xor=[u'assessor_id'],
+    reconstruction_id=dict(xor=['assessor_id'],
     ),
     server=dict(mandatory=True,
-    requires=[u'user', u'pwd'],
-    xor=[u'config'],
+    requires=['user', 'pwd'],
+    xor=['config'],
     ),
     share=dict(usedefault=True,
     ),
diff --git a/nipype/interfaces/tests/test_auto_XNATSource.py b/nipype/interfaces/tests/test_auto_XNATSource.py
--- a/nipype/interfaces/tests/test_auto_XNATSource.py
+++ b/nipype/interfaces/tests/test_auto_XNATSource.py
@@ -1,11 +1,12 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..io import XNATSource
 
 
 def test_XNATSource_inputs():
     input_map = dict(cache_dir=dict(),
     config=dict(mandatory=True,
-    xor=[u'server'],
+    xor=['server'],
     ),
     ignore_exception=dict(nohash=True,
     usedefault=True,
@@ -16,8 +17,8 @@ def test_XNATSource_inputs():
     query_template_args=dict(usedefault=True,
     ),
     server=dict(mandatory=True,
-    requires=[u'user', u'pwd'],
-    xor=[u'config'],
+    requires=['user', 'pwd'],
+    xor=['config'],
     ),
     user=dict(),
     )
diff --git a/nipype/interfaces/utility/tests/test_auto_AssertEqual.py b/nipype/interfaces/utility/tests/test_auto_AssertEqual.py
--- a/nipype/interfaces/utility/tests/test_auto_AssertEqual.py
+++ b/nipype/interfaces/utility/tests/test_auto_AssertEqual.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import AssertEqual
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_CSVReader.py b/nipype/interfaces/utility/tests/test_auto_CSVReader.py
--- a/nipype/interfaces/utility/tests/test_auto_CSVReader.py
+++ b/nipype/interfaces/utility/tests/test_auto_CSVReader.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..csv import CSVReader
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_Function.py b/nipype/interfaces/utility/tests/test_auto_Function.py
--- a/nipype/interfaces/utility/tests/test_auto_Function.py
+++ b/nipype/interfaces/utility/tests/test_auto_Function.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..wrappers import Function
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_IdentityInterface.py b/nipype/interfaces/utility/tests/test_auto_IdentityInterface.py
--- a/nipype/interfaces/utility/tests/test_auto_IdentityInterface.py
+++ b/nipype/interfaces/utility/tests/test_auto_IdentityInterface.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import IdentityInterface
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_Merge.py b/nipype/interfaces/utility/tests/test_auto_Merge.py
--- a/nipype/interfaces/utility/tests/test_auto_Merge.py
+++ b/nipype/interfaces/utility/tests/test_auto_Merge.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import Merge
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_Rename.py b/nipype/interfaces/utility/tests/test_auto_Rename.py
--- a/nipype/interfaces/utility/tests/test_auto_Rename.py
+++ b/nipype/interfaces/utility/tests/test_auto_Rename.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import Rename
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_Select.py b/nipype/interfaces/utility/tests/test_auto_Select.py
--- a/nipype/interfaces/utility/tests/test_auto_Select.py
+++ b/nipype/interfaces/utility/tests/test_auto_Select.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import Select
 
 
diff --git a/nipype/interfaces/utility/tests/test_auto_Split.py b/nipype/interfaces/utility/tests/test_auto_Split.py
--- a/nipype/interfaces/utility/tests/test_auto_Split.py
+++ b/nipype/interfaces/utility/tests/test_auto_Split.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..base import Split
 
 
diff --git a/nipype/interfaces/vista/tests/test_auto_Vnifti2Image.py b/nipype/interfaces/vista/tests/test_auto_Vnifti2Image.py
--- a/nipype/interfaces/vista/tests/test_auto_Vnifti2Image.py
+++ b/nipype/interfaces/vista/tests/test_auto_Vnifti2Image.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..vista import Vnifti2Image
 
 
@@ -21,7 +22,7 @@ def test_Vnifti2Image_inputs():
     out_file=dict(argstr='-out %s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s.v',
     position=-1,
     ),
diff --git a/nipype/interfaces/vista/tests/test_auto_VtoMat.py b/nipype/interfaces/vista/tests/test_auto_VtoMat.py
--- a/nipype/interfaces/vista/tests/test_auto_VtoMat.py
+++ b/nipype/interfaces/vista/tests/test_auto_VtoMat.py
@@ -1,4 +1,5 @@
 # AUTO-GENERATED by tools/checkspecs.py - DO NOT EDIT
+from __future__ import unicode_literals
 from ..vista import VtoMat
 
 
@@ -18,7 +19,7 @@ def test_VtoMat_inputs():
     out_file=dict(argstr='-out %s',
     hash_files=False,
     keep_extension=False,
-    name_source=[u'in_file'],
+    name_source=['in_file'],
     name_template='%s.mat',
     position=-1,
     ),