On Mar 6, 2006, at 4:14 PM, Guido van Rossum wrote: > On 3/6/06, Raymond Hettinger <[EMAIL PROTECTED]> wrote: >> [Neil Schemenauer] >>> I occasionally need dictionaries or sets that use object identity >>> rather than __hash__ to store items. Would it be appropriate to add >>> these to the collections module? >> >> Why not decorate the objects with a class adding a method: >> def __hash__(self): >> return id(self) >> >> That would seem to be more Pythonic than creating custom variants >> of other >> containers. > > I hate to second-guess the OP, but you'd have to override __eq__ too, > and probably __ne__ and __cmp__ just to be sure. And probably that > wouldn't do -- since the default __hash__ and __eq__ have the desired > behavior, the OP is apparently talking about objects that override > these operations to do something meaningful; overriding them back > presumably breaks other functionality. > > I wonder if this use case and the frequently requested > case-insensitive dict don't have some kind of generalization in common > -- perhaps a dict that takes a key function a la list.sort()?
+1. I've wanted such a thing a couple times, and there is some precedent in the stdlib (e.g. WeakKeyDictionary would be a lot shorter with such a base class). -bob _______________________________________________ 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
