45 lines
996 B
Python
45 lines
996 B
Python
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'''
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4.13. Special Attributes
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The implementation adds a few special read-only attributes to
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several object types, where they are relevant.
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Some of these are not reported by the dir() built-in function.
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https://docs.python.org/3/library/stdtypes.html#special-attributes
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'''
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obj_attrs = {'__dict__', '__class__'}
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cls_data_attrs = {'__slots__', '__bases__', '__name__', '__qualname__', '__mro__'}
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cls_methods = {'mro', '__subclasses__'}
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cls_attrs = cls_data_attrs | cls_methods
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an_object = object()
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class EmptyClass():
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pass
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an_instance = EmptyClass()
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class EmptySlots():
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__slots__ = ()
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a_slots_instance = EmptySlots()
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objs = EmptyClass, EmptySlots, an_object, an_instance, a_slots_instance
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for obj in objs:
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print('-' * 60)
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print(repr(obj), ':', type(obj))
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dir_obj = set(dir(obj))
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print('obj_attrs not listed:', sorted(obj_attrs - dir_obj))
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print('all cls_attrs :', sorted(cls_attrs))
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print('cls_attrs not listed:', sorted(cls_attrs - dir_obj))
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