From: Raymond Hettinger Date: Fri, 2 Apr 2010 04:49:24 +0000 (+0000) Subject: Fix nits in itertools recipes. X-Git-Tag: v3.1.3rc1~1004 X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=aeac26b9eadc17840857799f668341f508314518;p=python Fix nits in itertools recipes. --- diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index bb1208c363..5c63b12685 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -611,7 +611,7 @@ which incur interpreter overhead. def ncycles(iterable, n): "Returns the sequence elements n times" - return chain.from_iterable(repeat(iterable, n)) + return chain.from_iterable(repeat(tuple(iterable), n)) def dotproduct(vec1, vec2): return sum(map(operator.mul, vec1, vec2)) @@ -707,23 +707,23 @@ which incur interpreter overhead. def random_product(*args, repeat=1): "Random selection from itertools.product(*args, **kwds)" pools = [tuple(pool) for pool in args] * repeat - return [random.choice(pool) for pool in pools] + return tuple(random.choice(pool) for pool in pools) def random_permuation(iterable, r=None): "Random selection from itertools.permutations(iterable, r)" pool = tuple(iterable) r = len(pool) if r is None else r - return random.sample(pool, r) + return tuple(random.sample(pool, r)) def random_combination(iterable, r): "Random selection from itertools.combinations(iterable, r)" pool = tuple(iterable) - return sorted(random.sample(pool, r), key=pool.index) + return tuple(sorted(random.sample(pool, r), key=pool.index)) def random_combination_with_replacement(iterable, r): "Random selection from itertools.combinations_with_replacement(iterable, r)" pool = tuple(iterable) - return sorted(map(random.choice, repeat(pool, r)), key=pool.index) + return tuple(sorted(map(random.choice, repeat(pool, r)), key=pool.index)) Note, many of the above recipes can be optimized by replacing global lookups with local variables defined as default values. For example, the