Python @staticmethod vs @classmethod

Being educated under Java background, static method and class method are the same thing.

But not so in Python, there is subtle difference:

Say function a() is defined in Parent Class, while Sub Class extends Parent Class

If function a() has @staticmethod decorator, Sub.a() still refers to definition inside Parent Class. Whereas,

If function a() has @classmethod decorator, Sub.a() will points definition inside Sub Class.

Let’s talk about some definitions here:

@staticmethod function is nothing more than a function defined inside a class. It is callable without instantiating the class first. It’s definition is immutable via inheritance.

@classmethod function also callable without instantiating the class, but its definition follows Sub class, not Parent class, via inheritance. That’s because the first argument for @classmethod function must always be cls (class).

Reference:

• http://mail.python.org/pipermail/python-list/2007-July/450345.html

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