From 337cbbace0a43f50fcd33ea4d3b7cb30733237db Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Tue, 21 Nov 2017 00:23:34 -0800 Subject: Add comment and improve variable name in roundrobin() (#4486) --- Doc/library/itertools.rst | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index fa6c340..a918940 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -753,15 +753,16 @@ which incur interpreter overhead. def roundrobin(*iterables): "roundrobin('ABC', 'D', 'EF') --> A D E B F C" # Recipe credited to George Sakkis - pending = len(iterables) + num_active = len(iterables) nexts = cycle(iter(it).__next__ for it in iterables) - while pending: + while num_active: try: for next in nexts: yield next() except StopIteration: - pending -= 1 - nexts = cycle(islice(nexts, pending)) + # Remove the iterator we just exhausted from the cycle. + num_active -= 1 + nexts = cycle(islice(nexts, num_active)) def partition(pred, iterable): 'Use a predicate to partition entries into false entries and true entries' -- cgit v0.12