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Diffstat (limited to 'Doc/library/itertools.rst')
| -rw-r--r-- | Doc/library/itertools.rst | 10 |
1 files changed, 7 insertions, 3 deletions
diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index 6155322..d9a2b33 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -340,7 +340,7 @@ loops that truncate the stream. .. versionadded:: 2.6 -.. function:: product(*iterables) +.. function:: product(*iterables[, repeat]) Cartesian product of input iterables. @@ -353,11 +353,15 @@ loops that truncate the stream. so that if the inputs iterables are sorted, the product tuples are emitted in sorted order. + To compute the product of an iterable with itself, specify the number of + repetitions with the optional *repeat* keyword argument. For example, + ``product(A, repeat=4)`` means the same as ``product(A, A, A, A)``. + Equivalent to the following except that the actual implementation does not build-up intermediate results in memory:: - def product(*args): - pools = map(tuple, args) + def product(*args, **kwds): + pools = map(tuple, args) * kwds.get('repeat', 1) if pools: result = [[]] for pool in pools: |