Question

import os
import sys

class Corrector:

    def correctAll(dir):
        print "ok"

c = Corrector()
c.correctAll(os.getcwd())

This code is printing:

TypeError: correctAll() takes exactly
1 argument (2 given)

but AFAIK os.getcwd() returns a single string.. what’s wrong here?

Answer 1

You need to accept self as an argument or use the staticmethod decorator.

class Corrector:

    def correctAll(self, dir):
        print "ok"

or

class Corrector:

    @staticmethod
    def correctAll(dir):
        print "ok"

The distinction between the two is if you want the method to have access to the instance that it’s called on or not. If so, then use the first one and the the instance will be available as self. Otherwise, you can use the second one.

Python methods work by explicitly accepting the object that they are bound to as their first argument (self is canonical here but it can really be anything). That argument is then implicitly passed when a call occurs.