You are really gentle Raymond Hettinger, but surely I'm not asking you/anyone to write some code just for me; I don't have "real applications", I'm just learning/playing. Your words are quite good answers to most of my questions. The only left small topic is about the group/set-like operations/methods added to dicts; maybe some other person can comment that idea too. The semantic of such operations can be a little tricky, but sometimes they can avoid the use of sets (and the set-ify of dicts), sometimes they can carry the dict values with them (even if they work just on the dict keys), etc.
A bear hug, Bearophile -- http://mail.python.org/mailman/listinfo/python-list
