What is NotImplemented ?

[Alexandre Fayolle]

A quick question, here. What is the built in NotImplemented object? 
And what can you do with it? I thought I could raise it as an 
exception, but this is not the case (I use NotImplementedError instead).

 
Alexandre Fayolle
-- 
LOGILAB, Paris (France).
http://www.logilab.com   http://www.logilab.fr  http://www.logilab.org
Narval, the first software agent available as free software (GPL).