# Buggy code
def __getitem__(self, key):
    """Get the attribute corresponding to the given key."""
    # Catch NotImplementedError to fix #6284 in pandas MultiIndex
    # due to NA checking not being supported on a multiindex.
    # Catch AttributeError to fix #5642 in certain special classes like xml
    # when this method is called on certain attributes.
    # Catch TypeError to prevent fatal Python crash to desktop after
    # modifying certain pandas objects ( Issue #6727 ).
    try:
        attribute_toreturn = getattr(self.__obj__, key)
    except (NotImplementedError, AttributeError, TypeError):
        attribute_toreturn = None
    return attribute_toreturn


# Traceback (ValueError)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 528, in createEditor
readonly=readonly)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 1339, in setup
remote=remote)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 1287, in __init__
title)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 1164, in __init__
minmax=minmax)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 121, in __init__
self.set_data(data)
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 169, in set_data
self.set_size_and_type()
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 189, in set_size_and_type
for index in range(start, stop) ]
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 189, in <listcomp>
for index in range(start, stop) ]
File "C:\Users\C. A. M. Gerlach\Documents\dev\SpyderDev\spyder\spyder\widgets\variableexplorer\collectionseditor.py", line 86, in __getitem__
attribute_toreturn = getattr(self.__obj__, key)
File "C:\Anaconda3\envs\spyder-dev\lib\site-packages\pandas\tseries\offsets.py", line 530, in nanos
raise ValueError("{name} is a non-fixed frequency".format(name=self))
ValueError: <DateOffset> is a non-fixed frequency

# Fixed code
def __getitem__(self, key):
    """Get the attribute corresponding to the given key."""
    # Catch NotImplementedError to fix #6284 in pandas MultiIndex
    # due to NA checking not being supported on a multiindex.
    # Catch AttributeError to fix #5642 in certain special classes like xml
    # when this method is called on certain attributes.
    # Catch TypeError to prevent fatal Python crash to desktop after
    # modifying certain pandas objects. Fix issue #6727 .
    # Catch ValueError to allow viewing and editing of pandas offsets.
    # Fix issue #6728 .
    try:
        attribute_toreturn = getattr(self.__obj__, key)
    except (NotImplementedError, AttributeError, TypeError, ValueError):
        attribute_toreturn = None
    return attribute_toreturn