python 如何知道一个 method 是属于哪个class ？

Question

我希望可以判断一个 method 是属于哪个 class 的，要如何实现。

比如下面的代码，定义了一个 get_class_by_method 函数，参数是 method 接受函数类型，返回该函数归属的 class

from typing import Callable


class Work:
    def run(self):
        pass


class Reload:
    @classmethod
    def wait(cls):
        pass


def get_class_by_method(method: Callable) -> type:
    pass

比如, 通过下面的代码，获取对应的 class

get_class_by_method(Work().run)

又或者这样：

get_class_by_method(Reload.wait)

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插一个子问题：
我比较喜欢 python 的 typing hint，关于 get_class_by_method 的函数返回值，我注释为 type ，但是这让我是不是很满意，有什么更好的注释选择吗？

Answer 1

instance method 有一个 __self__ 属性：

datamodel

When an instance method object is created by retrieving a user-defined function object from a class via one of its instances, its __self__ attribute is the instance, and the method object is said to be bound. The new method’s __func__ attribute is the original function object.

When an instance method object is created by retrieving a class method object from a class or instance, its __self__ attribute is the class itself, and its __func__ attribute is the function object underlying the class method.