[Python-ideas] get method for sets?

[Mike Meyer]

On Thu, 17 May 2012 01:43:06 +1000
Ben Finney <ben+python at benfinney.id.au> wrote:
> Mike Meyer <mwm at mired.org> writes:
> > On Wed, 16 May 2012 17:39:10 +1000
> > Ben Finney <ben+python at benfinney.id.au> wrote:
> > > If by “get” you mean to get an *arbitrary* item, not a specific item,
> > > then what's the problem? You already have ‘set.pop’, as you point out.
> > And, as I also pointed out, it's not useful in the case where you need
> > to preserve the set for future use.
> Then, if ‘item = next(iter(foo_set))’ doesn't suit you, perhaps you'd
> like ‘item = set(foo_set).pop()’.

This is precisely what bugs me about this case. There's not one
obvious way to do it. There's a collection of ways that are all in
some ways/cases problematical. They all involve creating a scratch
object from the set and using it's API to (possibly destructively) get
the one value that's wanted. In a way, it reminds me of the
discussions that eventually led to the if else expression being added.

> Regardless, I think you have your answer: Like most things that can
> already be done by composing the existing pieces, this corner case
> hasn't met the deliberately-high bar for making a special method just to
> do it.

And it's already been discussed to death. *That's* what I was trying
to find out. If it hadn't been, I'd have put together a serious
proposal.

> I still haven't seen you describe the use case where the existing ways
> of doing this aren't good enough.

That, of course, is a subjective judgment.

      <mike
-- 
Mike Meyer <mwm at mired.org>		http://www.mired.org/
Independent Software developer/SCM consultant, email for more information.

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