> IMO the difference between ABCs and interfaces/abilities is that > inserting a new ABC into an existing class hierarchy without modifying > its source code is considered a hack, and must be done by a helper > routine that *actually* mucks with __bases__; while (Zope-style) > interfaces use an external registry or a separate class attribute > (__implements__) that is intended to be mucked with.
Right. That and also being able to assign interfaces to individual instances, being able to split and merge interfaces in a level that doesn't need changing the implementation itself, and so on. -- Gustavo Niemeyer http://niemeyer.net _______________________________________________ Python-3000 mailing list Python-3000@python.org http://mail.python.org/mailman/listinfo/python-3000 Unsubscribe: http://mail.python.org/mailman/options/python-3000/archive%40mail-archive.com
