Given a method return all the classes the method is implemented in

find_implementing_classes.py

def find_implementing_classes(method):
    """
    Given a method return all the classes the method is implemented in.
    a.aaa() -> A.aaa
    a.bbb() -> A.bbb
    b.aaa() -> A.aaa
    b.bbb() -> B.bbb
    A.aaa == B.aaa -> True
    A.bbb == B.bbb -> False
    find_implementing_classes(b.aaa) -> [<class '__main__.A'>]
    find_implementing_classes(b.bbb) -> [<class '__main__.B'>, <class '__main__.A'>]
    """
    mro = method.im_class.__mro__
    func_name = method.im_func.func_name
    impls = {}
    for i, cls in enumerate(mro):
        if hasattr(cls, func_name):
            impls[getattr(cls, func_name)] = (i, cls)
    return tuple(x[1] for x in sorted(impls.values()))