[Python-Dev] defaultdict proposal round three

[Raymond Hettinger]

[Alex]
>> I see d[k]+=1 as a substantial improvement -- conceptually more
>> direct, "I've now seen one more k than I had seen before".

[Guido]
> Yes, I now agree. This means that I'm withdrawing proposal A (new
> method) and championing only B (a subclass that implements
> __getitem__() calling on_missing() and on_missing() defined in that
> subclass as before, calling default_factory unless it's None). I don't
> think this crisis is big enough to need *two* solutions, and this
> example shows B's superiority over A.

FWIW, I'm happy with the proposal and think it is a nice addition to Py2.5.


Raymond