python - Check if a function uses @classmethod -

tl;dr how find out whether function defined using @classmethod or same effect?

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my problem

for implementing class decorator check if method takes class first argument, example achieved via

@classmethod def function(cls, ...): 

i found solution check @staticmethod via types module (isinstance(foo, types.unboundmethodtype) false if foo static, see here), did not find on how @classmethod

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context

what trying along lines of

def class_decorator(cls):     member in cls.__dict__:         if (isclassmethod(getattr(cls, member))):             # method             setattr(cls, member, modified_method)     return cls 

and not know how implement called isclassmethod in example

for python 2, need test both if object method, and if __self__ points class (for regular methods it'll none when retrieved class):

>>> class foo(object): ...     @classmethod ...     def bar(cls): ...         pass ...     def baz(self): ...         pass ...  >>> foo.baz <unbound method foo.baz> >>> foo.baz.__self__ >>> foo.baz.__self__ none true >>> foo.bar.__self__ <class '__main__.foo'> >>> foo.bar.__self__ foo true 

in python 3, regular methods show functions (unbound methods have been done away with).

combine inspect.ismethod() fail-safe method detect class method in both python 2 , 3:

import inspect  if inspect.ismethod(cls.method) , cls.method.__self__ cls:     # class method 

the method.__self__ attribute added in python 2.6 consistent python 3. in python 2.6 , 2.7 alias of method.im_self.