Instance methods vs. functions and the self parameter

[Henrik Hansen]

I am learning Python using the book "Practical Python", and have a 
little trouble understanding this example (I am familiar with OO 
concepts, having some experience with Java):

<example>

 >>> class Class:
         def method(self):
             print "I have a self!"

 >>> def function():
         print "I don't..."

 >>> instance = Class()
 >>> instance.method()
I have a self!
 >>> instance.method = function
 >>> instance.method()
I don't...

</example>

Ok, so I understand that you can assign instance.method to function, but 
what about the self argument? As I understand it, when calling a method 
like this: foo.bar() would be equivalent to calling like this (assuming 
that foo is an instance of class Baz): Baz.bar(foo). Is that correct?

In other words, why doesn't the function need to be declared 
function(self): ..., since it receives a parameter?

I must be wrong in some of my assumptions, some guidance would be 
appreciated.


-- 
Henrik Hansen