Function gen

Lib/test/test_generators.py:1915–1921

(i)

    values = [None] * len(gs)

    def gen(i):
        if i >= len(gs):
            yield values
        else:
            for values[i] in gs[i]():
                for x in gen(i+1):
                    yield x

    for x in gen(0):
        yield x