Python: can a decorator determine if a function is being defined inside a class?

Question

I\'m writing a decorator, and for various annoying reasons[0] it would be expedient to check if the function it is wrapping is being defined stand-alone or as part of a class (a

Answer 1

I think the functions in the inspect module will do what you want, particularly isfunction and ismethod:

>>> import inspect
>>> def foo(): pass
... 
>>> inspect.isfunction(foo)
True
>>> inspect.ismethod(foo)
False
>>> class C(object):
...     def foo(self):
...             pass
... 
>>> inspect.isfunction(C.foo)
False
>>> inspect.ismethod(C.foo)
True
>>> inspect.isfunction(C().foo)
False
>>> inspect.ismethod(C().foo)
True

You can then follow the Types and Members table to access the function inside the bound or unbound method:

>>> C.foo.im_func

>>> inspect.isfunction(C.foo.im_func)
True
>>> inspect.ismethod(C.foo.im_func)
False