[Python-Dev] Proposal: defaultdict

Guido van Rossum guido at python.org
Sat Feb 18 01:20:46 CET 2006

On 2/17/06, "Martin v. Löwis" <martin at v.loewis.de> wrote:
> That's why I think has_key and in should return True for any key.
> This leaves keys(), items(), and values(). From a pure point of
> view, they should return infinite sets. Practicality beats purity,
> so yes, d[k] could be considered a modifying operation.

I think practicality beats purity even for has_key/in; IMO these
operations are more useful when they match keys() instead of always
returning True. But someone should start writing some code to play
with this.

I have a working patch (including a hack for PyDict_GetItem()):

So there's no excuse to be practical now.

--Guido van Rossum (home page: http://www.python.org/~guido/)

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