bpo-31270: Simplify documentation of itertools.zip_longest

[raphaelm]

https://bugs.python.org/issue31270

[the-knights-who-say-ni]

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[raphaelm]

CLA is signed and submitted. Do I need to write a NEWS entry for this? I think it's rather "skip news", right?

[Mariatta]

Thanks @raphaelm, I think news can be skipped for this one :)

[raphaelm]

Hi @Mariatta, thanks for the quick answer! :)

[rhettinger]

I prefer code that is closer to the actual implementation:

    def zip_longest(*args, **kwds):
        # zip_longest('ABCD', 'xy', fillvalue='-') --> Ax By C- D-
        fillvalue = kwds.get('fillvalue')
        iterators = [iter(it) for it in args]
        num_active = len(iterators)
        while True:
            values = []
            for i, it in enumerate(iterators):
                if it is None:
                    value = fillvalue
                else:
                    try:
                        value = next(it)
                    except StopIteration:
                        num_active -= 1
                        value = fillvalue
                        iterators[i] = None
                values.append(value)
            if not num_active:
                return
            yield tuple(values)

Also, please keep the leading whitespace the same as the original. Likewise, don't introduce blank lines into the code equivalents.

[rhettinger]

See alternate implementation in the comments.

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[rhettinger]

Moving this to an alternate pull request #3427