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class Boom:
 def __dir__(self):
 return ['BOOM']
 def __getattr__(self, name):
 if name =='BOOM':
 return 42
 return super().__getattr(name)
help(Boom)
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Help on class Boom in module __main__:
class Boom(builtins.object)
 | Methods defined here:
 | 
 | __dir__(self)
 | 
 | __getattr__(self, name)
 | 
 | ----------------------------------------------------------------------
 | Data descriptors defined here:
 | 
 | __dict__
 | dictionary for instance variables (if defined)
 | 
 | __weakref__
 | list of weak references to the object (if defined)
(END)
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So on an instance there is no problem.
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import inspect
class MetaBoom(type):
 def __dir__(cls):
 return ['__class__', '__module__', '__name__', 'BOOM']
 def __getattr__(self, name):
 if name =='BOOM':
 return 42
 return super().__getattr(name)
 def test(self):
 print('testing...')
class Boom(metaclass=MetaBoom):
 pass
help(Boom())
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Help on Boom in module __main__ object:
<class '__main__.Boom'>
(END)
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Still have problem with metaclasses.
Looking at the result from inspect.classify_class_attrs() we see:
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Attribute(name='BOOM', kind='data', defining_class=None,
 object=<object object at 0x7f061f04d200>)
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The defining class for BOOM should be Boom, not None.
With the attached patch, we get:
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Help on Boom in module __main__ object:
class Boom(builtins.object)
 | Data and other attributes defined here:
 | 
 | BOOM = 42
(END)
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