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def always_iterable(obj, base_type=(str, bytes)): |
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"""If *obj* is iterable, return an iterator over its items:: |
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>>> obj = (1, 2, 3) |
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>>> list(always_iterable(obj)) |
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[1, 2, 3] |
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If *obj* is not iterable, return a one-item iterable containing *obj*:: |
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>>> obj = 1 |
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>>> list(always_iterable(obj)) |
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[1] |
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If *obj* is ``None``, return an empty iterable: |
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>>> obj = None |
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>>> list(always_iterable(None)) |
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[] |
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By default, binary and text strings are not considered iterable:: |
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>>> obj = 'foo' |
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>>> list(always_iterable(obj)) |
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['foo'] |
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If *base_type* is set, objects for which ``isinstance(obj, base_type)`` |
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returns ``True`` won't be considered iterable. |
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>>> obj = {'a': 1} |
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>>> list(always_iterable(obj)) # Iterate over the dict's keys |
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['a'] |
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>>> list(always_iterable(obj, base_type=dict)) # Treat dicts as a unit |
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[{'a': 1}] |
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Set *base_type* to ``None`` to avoid any special handling and treat objects |
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Python considers iterable as iterable: |
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>>> obj = 'foo' |
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>>> list(always_iterable(obj, base_type=None)) |
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['f', 'o', 'o'] |
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""" |
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if obj is None: |
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return iter(()) |
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if (base_type is not None) and isinstance(obj, base_type): |
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return iter((obj,)) |
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try: |
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return iter(obj) |
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except TypeError: |
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return iter((obj,)) |
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