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def handle_error(index):
    if index == 0:
        for index, it in enumerate(iterators):
            try:
                next(it)
                break
            except StopIteration:
                pass
        else:
            return
        compares = "longer"
    else:
        compares = "shorter"
    end_index = "" if index == 1 else f"-{index}"
    raise ValueError(f"zip() argument {index + 1} is {compares} than arguments 1{end_index}")


def zip_it(*iterables, strict=False):
    iterators = [iter(it) for it in iterables]
    if iterators:
        while True:
            try:
                zipped = []
                for it in iterators:
                    zipped.append(next(it))
            except StopIteration:
                if strict:
                    handle_error(iterators, len(zipped))
                break
            else:
                yield tuple(zipped)

Code: Alles auswählen

def count_exhausted(iterators):
    exhausted = []
    for it in iterators:
        try:
            next(it)
        except StopIteration:
            exhausted.append(it)
    return len(exhausted)

def build_exception(relation, position):
    maybe_plural = "s 1-" if position > 2 else " "
    return ValueError(
        f"zip_it() argument {position} is {relation} than "
        f"argument{maybe_plural}{position - 1}"
    )

def zip_it(*iterables, strict=False):
    if not iterables:
        return
    iterators = [iter(it) for it in iterables]
    while True:
        zipped = tuple(map(next, iterators))
        if len(zipped) < len(iterators):
            if not strict:
                break
            if zipped:
                raise build_exception("shorter", len(zipped) + 1)
            num_exhausted = count_exhausted(iterators)
            if num_exhausted == len(iterators):
                break
            raise build_exception("longer", num_exhausted + 1)
        yield zipped