What happens when a __call__ function is defined in both class and object ?

[Chris Angelico]

On Thu, Oct 19, 2017 at 7:11 PM, ast <nomail at com.invalid> wrote:
> Hello, please have a look at following code snippet
> (python 3.4.4)
>
> class Test:
>
>    a = 1
>
>    def __init__(self):
>        self.a = 2
>        self.f = lambda : print("f from object")
>        self.__call__ = lambda : print("__call__ from object")
>     def __call__(self):
>        print("__call__ from class Test")
>     def f(self):
>        print("f from class Test")
>
> test=Test()
>
>>>> test.a
>
> 2
> ok, a is defined in both the class and the object, it is read from
> the object. This is the expected behavior
>
>>>> test.f()
>
> f from object
>
> ok for the same reason
>
>>>> test()
>
> __call__ from class Test
>
>
> Surprisingly, __call__ from the class is called, not the
> one defined in the object. Why ?

That's the way most dunder methods (those with "d"ouble "under"scores
before and after their names) work.