Carl Banks <[EMAIL PROTECTED]> wrote: > [EMAIL PROTECTED] wrote: > > The extra_information is used in MetaThing to tell it what attributes > > to add to the class. For example: > > > > class MetaThing(type): > > def __init__(cls, name, bases, dict, extra_information): > > super(MetaThing, cls).__init__(name, bases, dict) > > #setup the class based on the parameter extra_information > > setattr(cls, make_name(extra_information), > > make_object(extra_information)) > > > > Does that clarify things? > > Why do the extra attributes need to be part of the class? ISTM each > instance has its own class; therefore there it doesn't matter whether a > member is a class member or an instance member.
It matters for a "member" that is actually a special-method: Python's automatic search for special methods (except on old-style classes) does NOT look at per-instance members, only at per-class ones. But, as many have already said, a custom metaclass is probably not the optimal tool for this task (and it's definitely wrong to alter a metaclass's __init__'s signature in incompatible ways -- you would never be able to make classes with metaclass MetaThing with a normal class statement, since the intrinsic call to the metaclass's __init__ fails!). Alex -- http://mail.python.org/mailman/listinfo/python-list
