I'm definitely in preference to slot versus attribute. But may be we could just use def. class Foo: def a def b def c def somemethod(self): pass The distinction being the def statement is "unbound" so to speak. humm.... the code is not clear enough. class Foo: slot a slot b slot c def foo(): pass Better, much better. class Foo: slot a is str slot b is float slot c is property of float def foo(self): pass I like this. It reads like sentences. (remember, 'of' modified property to ensure that the fget return type would be correct and fset passed in object would be correct) I didn't much care for Groucho's notation, particularly if a slot could have multiple types, why bother assigning types to it at all. It should definitely be singular. One to one. The concept of slot does not need to be solely related to attributes within a class. Why not reserve slots for a methods, classes within a module, modules imported within modules. Then it will be easier to see the overall picture. Does the slot pattern relate to every object in python? I think it does. That's when the real benefit comes in. If python could utilize this pattern in every aspect, the big performance boost will occur. In a strange way slots has made python even more dynamic than it ever was. Prior to slots, objects had a static c structure. Slots enables variability in another dimension for the underlying C struct. On the outside it looks like python is becoming static, but what's really going on under the hood is quite the contrary. Definitely more burden on the compiler to build correct references and make the correct substitutions. __________________________________________________ Do You Yahoo!? Got something to say? Say it better with Yahoo! Video Mail http://mail.yahoo.com