diff --git a/Doc/library/itertools.rst b/Doc/library/itertools.rst index b3a0a5f5192..a3f403a5b40 100644 --- a/Doc/library/itertools.rst +++ b/Doc/library/itertools.rst @@ -691,6 +691,12 @@ Itertools Recipes This section shows recipes for creating an extended toolset using the existing itertools as building blocks. +Substantially all of these recipes and many, many others can be installed from +the `more-itertools project `_ found +on the Python Package Index:: + + pip install more-itertools + The extended tools offer the same high performance as the underlying toolset. The superior memory performance is kept by processing elements one at a time rather than bringing the whole iterable into memory all at once. Code volume is @@ -913,9 +919,3 @@ which incur interpreter overhead. result.append(pool[-1-n]) return tuple(result) -Note, many of the above recipes can be optimized by replacing global lookups -with local variables defined as default values. For example, the -*dotproduct* recipe can be written as:: - - def dotproduct(vec1, vec2, sum=sum, map=map, mul=operator.mul): - return sum(map(mul, vec1, vec2))