Author: raymond.hettinger Date: Sun Mar 28 20:08:15 2010 New Revision: 79481 Log: Add a note on optimizing the itertools recipes for production. Modified: python/trunk/Doc/library/itertools.rst Modified: python/trunk/Doc/library/itertools.rst ============================================================================== --- python/trunk/Doc/library/itertools.rst (original) +++ python/trunk/Doc/library/itertools.rst Sun Mar 28 20:08:15 2010 @@ -784,3 +784,9 @@ except exception: pass +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, imap=imap, mul=operator.mul): + return sum(imap(mul, vec1, vec2))