[Python-Dev] Re: Sets

[Guido van Rossum]

> But what sense would it make to force sets to expose
> a __getitem__?  Right now they inherit from dict and
> thus do happen to expose it, but that's really an
> implementation artefact showing through (and a good
> example of why one might like to inherit without needing
> to expose all of the superclass's interface, to tie this in
> to another recent thread -- inheritance for implementation).
> 
> Ideally, sets would expose __contains__, __iter__, __len__,
> ways to add and remove elements, and perhaps (it's so in
> Greg's implementation, and I didn't touch that) set ops such
> as union, intersection &c.  someset[anindex] is really a weird
> thing to have... yet sets _are_ containers!

I believe I recommended to Greg to make sets "have" a dict instead of
"being" dicts, and I think he agreed.  But I guess he never got to
implementing that change.

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