How are methods, `classmethod`, and `staticmethod` implemented in Python?

user_99989 0
Viewed 10279

At what point do methods in Python acquire a get property? —As soon as they're defined in the class? Why does Python let me define a method without any arguments (not even a first self argument)?

I know how to use classmethod and staticmethod, and I know that they're built-in functions, but what happens to a function that is so-decorated?

Essentially, I'm wondering about the "magic" that happens between class definition and class construction.

built-in methods class python
2 Answers

For reference, from the first link in @JAB's answer

Using the non-data descriptor protocol, a pure Python version of staticmethod() would look like this:

class StaticMethod(object):
    "Emulate PyStaticMethod_Type() in Objects/funcobject.c"

    def __init__(self, f):
        self.f = f

    def __get__(self, obj, objtype=None):
        return self.f

...

Using the non-data descriptor protocol, a pure Python version of classmethod() would look like this:

class ClassMethod(object):
    "Emulate PyClassMethod_Type() in Objects/funcobject.c"

    def __init__(self, f):
        self.f = f

    def __get__(self, obj, klass=None):
        if klass is None:
            klass = type(obj)
        def newfunc(*args):
            return self.f(klass, *args)
        return newfunc
user_114116860
Related