Python - monkeypatch a method on a class and call the original method from the new one

monkeypatch_partialmethod.py

#!/usr/bin/env python
#
# monkeypatch a method on a class and call the original method from the new one


from functools import partialmethod


class MyClass:
    # this is the original method
    def my_method(self):
        print("hello from the original method")


# this is a function that replaces the original method
def my_method(self, orig):
    print("hello from the replacement method")
    # orig here is the original method, so can be called like this:
    orig(self)


# this makes the function a method on the class
MyClass.my_method = partialmethod(my_method, MyClass.my_method)


# example usage
if __name__ == "__main__":
    foo = MyClass()
    foo.my_method()