set using alternative hash function?

[Austin Bingham]

I guess we see things differently. I think it's quite natural to want
a set of unique objects where "unique" is defined as an operation on
some subset/conflation/etc. of the attributes of the elements. That's
all that the regular set class is, except that it always uses the
hash() function to calculate uniqueness. In any event, the notions of
set and uniqueness I'm using are well established in other languages,
so I don't see why it couldn't be made to work in python.

As far as using a dict, that doesn't really solve my problem. It could
be part of a solution, I guess, but I would still need functionality
extrinsic to the dict. What I want is to make sure that no values in
my set have the same name, and dict won't guarantee that for me. A set
that calculated uniqueness based on its elements' names, on the other
hand, would.

Austin

On Thu, Oct 15, 2009 at 1:48 PM, Duncan Booth
<duncan.booth at invalid.invalid> wrote:
> It doesn't make sense to use just part of an object as the key for a set. A
> set is just a collection of values and there is no key separate from the
> value itself. If you build a set from x.name then that works fine, but only
> the names are stored.
>
> What you want in this particular case is a dict: a dict stores both a key
> and a value and lets you retrieve the value from the key.
>
>
> --
> Duncan Booth http://kupuguy.blogspot.com
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>