How to get a class of a method?

November 22, 2023

I created a decorator for a method in my class, but inside the decorator, I need to get the class of the method. How can I do that?

Here is the code of what I am trying to do:

def my_decorator(method):
    a = # The class of "method"
    print(a)  # <class '__main__.MyClass'>

class MyClass:
    @my_decorator
    def my_method(self, *args, **kwargs):
        ...

>Solution :

First you need to fix the decorator… you get the reference of the class as the first argument passed to the __wrapper. To get the parameter identifier you can use a code object and then use it as the key of locals.

Notice that this method is sensible on the signature of the decorator. In this case the last [0] is needed only because the first argument is *args,a tuple, and the first entry is needed.

def my_decorator(method):
    def __wrapper(*args, **kwargs):
        cls = locals()[__wrapper.__code__.co_varnames[0]][0]

        print(type(cls))
        print(hasattr(cls, method.__name__))
        return method(*args, **kwargs)
    return __wrapper


class MyClass:
    @my_decorator
    def my_method(self, *args, **kwargs):
        pass


MyClass().my_method()

Output