[Python-3000] ABC PEP -- dropping set.clear

Guido van Rossum guido at python.org
Thu Apr 26 02:39:38 CEST 2007

On 4/25/07, Jim Jewett <jimjjewett at gmail.com> wrote:
> On 4/25/07, guido.van.rossum <python-checkins at python.org> wrote:
> > +        implementation.)  **Open issues:** Forcing every mutable set
> > +        to implement this may be a pain for such a fairly
> > +        non-essential method.  Perhaps just drop it?
> There are also comments worrying that an abstract implementation would
> be horribly slow -- but so what?

True. In the discussion of __hash__ returning 0 by default I even
mention that I'd rather be slow and correct than fast and wrong. :-)

> Alex Martelli posted some stats (for dicts, I think) showing that
> (even today) clear was slower than just creating a new object.


> It still makes sense if you care about the "is" relation
> Since you are keeping "pop", the abstract implementation can at least
> approximate iteration.
>     def clear(self):
>         while self.pop(): pass

That would have to be

  def clear(self):
    while True:
      except KeyError:

But yeah, I'll do this. Thanks for the reality check!

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

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