The need to put "self" in every method

[Ron Adam]

Fernando M. wrote:
> Hi,
> 
> i was just wondering about the need to put "self" as the first
> parameter in every method a class has because, if it's always needed,
> why the obligation to write it? couldn't it be implicit?
> 
> Or is it a special reason for this being this way?
> 
> Thanks.

Here's how I view it...  (It may not be strictly correct, so corrections 
are welcome.)

It helps to think of new style class's as code patterns or templates to 
create class-instance objects.  Since you don't know what the name of 
the instance object is going to be when you write the class, a way to 
refer to the contents of the not yet created object is needed.

Passing the class-instance reference as the first argument is how Python 
gets a reference to the local name space of the method.  You can then 
use that name to access the other objects in the class-instance or to 
create new objects in the class-instance from within the method without 
knowing what the class-instance name is before hand.

Python doesn't pass the 'self' reference when a locally defined function 
is called inside a class or method.  By having to *explicitly* receive 
the 'self' reference in the argument list, it is clear when the 'self' 
reference is available for use and when it's not.

Cheers,
_Ron_Adam