Can python have class or instance methods that do not have "self" as the first argument?

Question

Possible Duplicate:
Why do you need explicitly have the “self” argument into a Python method?
Python ‘self’ explained

This is just for my own edification. I am learning python and have moved into OOP with python. Every single example of a method in a class that I have seen has "self" as the first argument. Is this true of all methods? If it is true, couldn't python have been written so that this argument was just understood and therefore not needed? Thanks.

and [What is the advantage of having this/self pointer mandatory explicit?](http://stackoverflow.com/q/910020) — Martijn Pieters, Jan 14 '13 at 22:20
instance methods are passed the instance as first argument, class methods the class — Facundo Casco, Jan 14 '13 at 22:21
Based on one of the existing answers, this question isn't a 100% duplicate. I'm voting to reopen. — Mark Ransom, Jan 14 '13 at 22:27
Certainly sounds like a duplicate, granted, but the answers to that other question really aren't getting at my question, with the exception of one answer that links to Guido's blog, and I can't read that to confirm right now because of a firewall problem. — bob.sacamento, Jan 14 '13 at 22:30

score 20 · Accepted Answer · answered Jan 14 '13 at 22:23

If you want a method that doesn't need to access self, use staticmethod:

class C(object):
    def my_regular_method(self, foo, bar):
        pass
    @staticmethod
    def my_static_method(foo, bar):
        pass

c = C()
c.my_regular_method(1, 2)
c.my_static_method(1, 2)

If you want access to the class, but not to the instance, use classmethod:

class C(object):
    @classmethod
    def my_class_method(cls, foo, bar):
        pass

c.my_class_method(1, 2)

Just learned something new. Thanks. – bob.sacamento Jan 14 '13 at 23:14 — bob.sacamento, Jan 14 '13 at 23:14

score 3 · Answer 2 · edited May 23 '17 at 12:24

3

static methods don't need self~~, they operate on the class~~

see a good explanation of static here: Static class variables in Python

edited May 23 '17 at 12:24

Community

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answered Jan 14 '13 at 22:22

neu-rah

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Static methods don't operate on the class; they have no reference to the class other than the class name itself. – Ignacio Vazquez-Abrams Jan 14 '13 at 22:23

Can python have class or instance methods that do not have "self" as the first argument?

2 Answers2

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