Can __iter__ be used as a classmethod?

[Alex Martelli]

Aahz wrote:
   ...
>>    """Subclasses of Frozen are frozen, i.e. it is impossible to add
>>     new attributes to them and their instances, except via inheritance"""
   ...
> Why the heck didn't you use __slots__?!?!?!

Just using __slots__ (without a custom metaclass) would NOT "freeze" any
subclass: just by subclassing, you'd get instances to which attributes
could freely be added.

A custom metaclass might well be a more suitable approach, of course,
and it could, in particular. use __slots__ to optimize things.


Alex