[Python-3000] PEP 3106: Revamping dict.keys(), .values() and .items() (original) (raw)

Delaney, Timothy (Tim) tdelaney at avaya.com
Wed Dec 20 21:40:01 CET 2006

Talin wrote:

1) values() should be documented as list-like rather than set-like. (Or better yet bag-like, but Python doesn't have bags. In other words, it's really an unordered collection of items with no special indexing semantics or uniqueness constraint.)

My reasoning is that generally people don't expect to be able to do set membership tests of the values of a mapping; Mostly, values() is used for iteration. And given that all of the set-like operations are slow, let's just cut to the chase and say that values() isn't a set at all.

I almost agree here, but the property that multiset(1, 2, 2) == multiset(2, 1, 2) seems useful for a dict values view.

OTOH, how many people have complained that given d1 == d2, d1.values() may not equal d2.values() in 2.x? I've definitely never had any problems with it, but then again, I find it rare that I've needed values().

Tim Delaney

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