"M.-A. Lemburg" wrote:
Could someone please first explain what these slots are used for in the first place :-? There must be some difference to standard class attributes... which is probably also the reason for the above behaviour (even though it does look like a bug to me).
My understanding is that the slots define the set of attributes-like things that instances of that class can have. It 'robs' the instances of such classes from having a __dict__ (at least conceptually), and provides much lighter weight attributes. Instances only need to store the _values_ in a struct/array, while the set of slot names and their order (in memory) is kept at the class level. This sort of thing is helpful from a memory point of view when you're dealing with e.g. large numbers of similar objects which all share the same attribute set (coordinates, Tk labels, whatnot). It doesn't explain (to me at least) why the lookup order is different. --david