Raymond Hettinger wrote: > Aside: Why on_missing() is an oddball among dict methods. When > teaching dicts to beginner, all the methods are easily explainable ex- > cept this one. You don't call this method directly, you only use it > when subclassing, you have to override it to do anything useful, it > hooks KeyError but only when raised by __getitem__ and not > other methods, etc.
agreed. > My recommendation: Dump the on_missing() hook. That leaves > the dict API unmolested and allows a more straight-forward im- > plementation/explanation of collections.default_dict or whatever > it ends-up being named. The result is delightfully simple and easy > to understand/explain. agreed. a separate type in collections, a template object (or factory) passed to the constructor, and implementation inheritance, is more than good en- ough. and if I recall correctly, pretty much what Guido first proposed. I trust his intuition a lot more than I trust the design-by-committee-with- out-use-cases process. </F> _______________________________________________ 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
