> The implementation is certainly a design decision. setdefault() could be > implemented in terms of __set/getitem__() as > > def setdefault(self, key, value=None): > try: > return self[key] > except KeyError: > self[key] = value > return self[key] > > I guess it's not done for performance reasons.
Nope. What if you changed your default value? Then you'd have to update the whole dictionary - but without keeping track of the keys you placed the default value under that isn't possible. Which strikes me as more-than-marginal overhead - without any advantage (as using __setitem__ for the default value isn't something I consider being a missing feature...) Diez -- http://mail.python.org/mailman/listinfo/python-list
