Le Tue, 10 Sep 2013 13:24:29 +0100, Paul Moore <p.f.mo...@gmail.com> a écrit : > On 10 September 2013 13:00, Nick Coghlan <ncogh...@gmail.com> wrote: > > Is this just syntactic sugar for recursive lookup of a transformed > > version in __missing__? Or a way of supplying a custom "key" > > function to a dictionary? > > Not quite, because the dict should preserve the originally entered > key. > > >>> td['FOO'] = 42 > >>> td['bar'] = 1 > >>> td['foo'] > 42 > >>> td['BAR'] > 1 > >>> list(td.keys()) > ['FOO', 'bar'] > > This actually prompts the question, what should the following produce: > > >>> td['FOO'] = 42 > >>> td['foo'] = 32 > >>> list(td.keys()) > > ['FOO'] or ['foo']? Both answers are justifiable. Both are possibly > even useful depending on context...
I think it would be best to leave it as an implementation detail, because whichever is easiest to implement depends on the exact implementation choices (e.g. C vs. Python). (my prototypes right now conserve the last __setitem__ key, not the first) Regards Antoine. _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
