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Add comment and improve variable name in roundrobin() (#4486)

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Raymond Hettinger 2017-11-21 00:23:34 -08:00 committed by GitHub
parent bc9b6e29cb
commit 337cbbace0
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1 changed files with 5 additions and 4 deletions
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9
Doc/library/itertools.rst
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@ -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'