Ian Bicking: the old part of his blog

Re: More on Python Metaprogramming

The "attribute creation without assignment" thing (like the implements() and advise() examples you brought up) was considered for Django, but we ended up deciding it was too much magic and could confuse experienced Python programmers. Check out http://code.djangoproject.com/attachment/ticket/122/proof_of_concept.py for the proof-of-concept implementation by Robin Munn, if only because it's an interesting hack. :)

Comment on More on Python Metaprogramming
by Adrian Holovaty