Re: [Python-ideas] Support other dict types for type.__dict__

An easy way to create immutable instances is 'collections.namedtuple': X = namedtuple("X", "a b") x = X(a=4, b=2) x.a + x.b # fine x.a = 5 # AttributeError: can't set attribute x.c = 5 # AttributeError: 'X' object has no attribute 'c' Tricks using 'object.__setattr__()' etc. will fail since the instance doesn't have a '__dict__'. The only data in the instance is stored in a tuple, so it's as immutable as a tuple. You can also derive from 'X' to add further methods. Remember to set '__slots__' to an empty iterable to maintain immutability. Cheers, Sven