Thomas Heller wrote: > playing a little with py3k... > > pep3115 mentions that "__prepare__ returns a dictionary-like object > which is used to store the class member definitions during evaluation > of the class body." > > It does not mention whether this dict-like object is used afterwards > as the class-dictionary of the created class or not (when the __new__ > method of the metaclass is called).
The intention is that it's up to the metaclass to decide. I suspect that most metaclasses won't want to use the dict-like object as the class dict, for two reasons: 1) The behavior of assigning to the class dict after class creation is likely to be different than the behavior of assignment during class creation. In particular, a typical 'dict-like' object is likely to be slower than a dict (it has more work to do, after all), and you don't want that slowness around once your class is finished initializing. 2) A 'dict-like' object doesn't have to support all of the methods of a real dict, wherease a class dict does. So your dict-like wrapper can be relatively simple. -- Talin _______________________________________________ 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
