Methods of setting class attributes

[Piotr Legiecki]

Hi

I'm C++ user and new to Python. I don't know what is the proper method
of setting attribute value in a class. I thought that this is ok:

class a:
  atr1=0
  atrb=1
.....

Well, after a little tour through python source codes I have changed my
point of view.

1. There is no explicit attributes declarations (hm...)
2. I'v found such a information in python's docs:
......

__setattr__(s, name, val) called when setting an attr
                                  (inside, don't use "self.name = value"
                                   use "self.__dict__[name] = val")
.....

This method (among others) has any class. So setting any attribute
should always be done by __setattr__() and not smiple self.name = value?
Why?

-- 
Regards
Piotr Legiecki