[Python-3000] Need help completing ABC pep

[Brett Cannon]

On 4/19/07, Guido van Rossum <guido at python.org> wrote:
> I've started a PEP on Abstract Base Classes (ABCs), PEP 3119:
>
>     http://www.python.org/dev/peps/pep-3119/
>
> While I'm not ready yet to answer tough questions about this compared
> to alternative proposals, I *am* ready for feedback on the various
> open issues sprinkled throughout the current text, especially
> concerning decisions regarding exactly which operations to include in
> the various ABCs, and also regarding the level of detail required in
> the PEP.
>

Just noticed your latest checkin asks whether to unify 'remove' and
'discard' for sets.  I say yes.  If people care about whether the item
pre-exists or not they can check if the item is contained in the set
since it implements Container.  So either have it throw an exception
if the item does not exist or return a boolean based on whether
something was remove ala Java.  But I don't see a need for both when
the check is as simple as::

  set.remove(item) if item in set else None

or something along those lines.

-Brett