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| -rw-r--r-- | Doc/library/itertools.rst | 8 |
1 files changed, 7 insertions, 1 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 4f82a27..f83e976 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -672,7 +672,13 @@ which incur interpreter overhead. def consume(iterator, n): "Advance the iterator n-steps ahead. If n is none, consume entirely." - collections.deque(islice(iterator, n), maxlen=0) + # Use functions that consume iterators at C speed. + if n is None: + # feed the entire iterator into a zero-length deque + collections.deque(iterator, maxlen=0) + else: + # advance to the emtpy slice starting at position n + next(islice(iterator, n, n), None) def nth(iterable, n, default=None): "Returns the nth item or a default value" |