[Tutor] static methods & class methods

Prasad, Ramit ramit.prasad at jpmorgan.com
Fri Apr 20 18:00:58 CEST 2012

> I have a class, and want to use a method of it in the class itself.
> How can I do it?
> I mean, say I defined foo() , bar() methods in a class myClass. So, how
> can we i use foo() in bar(). I tried to use @staticmethod, @classmethod,
> but I am getting some errors..
> sometimes saying "unbound " and sometimes "given more than 1 parameters"
> .. can any one tell me how to do this...

You should read about object oriented programming in Python. 
http://www.alan-g.me.uk/tutor/index.htm is a good starting point (on the 
left under 'Advanced Topics'). 

I take this to mean you want to call a method in the class from another
method in the class. I assume you do not need to use "staticmethod" and
do something like below:

class A 
    Method foo:
        <do something>
    Method bar
        < do something including calling foo >

Every method in a class *must* take in the instance. The convention 
is to call this "self". To access another method you use the instance 
and call the method desired. An unbound function is a function that
is not tied to an object/class. This is also why you got "given more 
than 1 parameters" error. I assume you did not include self in the 
function definition and Python was passing it. This becomes the 

class A( object ): # I use Python 2.x
    def foo( self ): # must include self
        print 'foo'
    def bar( self ):
        print 'bar'
        self.foo() # This uses the instance to call foo


Ramit Prasad | JPMorgan Chase Investment Bank | Currencies Technology
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