[Noam] > For example, iteration over a set which once had > 1,000,000 members and now has 2 can take 1,000,000 operations every > time you traverse all the (2) elements.
Do you find that to be a common or plausible use case? Was Guido's suggestion of s=set(s) unworkable for some reason? dicts and sets emphasize fast lookups over fast iteration -- apps requiring many iterations over a collection may be better off converting to a list (which has no dummy entries or empty gaps between entries). Would the case be improved by incurring the time cost of 999,998 tests for possible resizing (one for each pop) and some non-trivial number of resize operations along the way (each requiring a full-iteration over the then current size)? Even if this unique case could be improved, what is the impact on common cases? Would a downsizing scheme risk thrashing with the over-allocation scheme in cases with mixed adds and pops? Is there any new information/research beyond what has been obvious from the moment the dict resizing scheme was born? Raymond _______________________________________________ Python-Dev mailing list Python-Dev@python.org http://mail.python.org/mailman/listinfo/python-dev Unsubscribe: http://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
