Pre-PEP: Dictionary accumulator methods

[Raymond Hettinger]

[Roose]
> I like this, it is short, low impact, and makes things more readable.  I
> tend to go with just the literal way of doing it instead of using get and
> setdefault, which I find awkward.

Thanks.  Many people find setdefault() to be an oddball.


> But alas I had a my short, low impact, useful suggestion and I think it
> died.  It was for any() and all() for lists.  Actually Google just released
> their "functional.py" module on code.google.com with the exact same thing.
> Except they are missing the identity as a default which is very useful, i.e.
> any(lst, f=lambda x: x) instead of any(lst, f).
>
> Maybe you can tack that onto your PEP :)

Py2.5 is already going to include any() and all() as builtins.  The signature
does not include a function, identity or otherwise.  Instead, the caller can
write a listcomp or genexp that evaluates to True or False:

    any(x >= 42 for x in data)

If you wanted an identify function, that simplifies to just:

    any(data)


Raymond Hettinger