assert not callable(1)


def f():
    pass


assert callable(f)
assert callable(len)
assert callable(lambda: 1)
assert callable(int)


class C:
    def __init__(self):
        # must be defined on class
        self.__call__ = lambda self: 1

    def f(self):
        pass


assert callable(C)
assert not callable(C())
assert callable(C().f)


class C:
    def __call__(self):
        pass


assert callable(C())


class C1(C):
    pass


assert callable(C1())


class C:
    __call__ = 1


# CPython returns true here, but fails when actually calling it
assert callable(C())