On Mon, 22 Mar 2010 22:19:57 +0000, kj wrote: > In <mailman.1069.1269283393.23598.python-l...@python.org> Tim Golden > <m...@timgolden.me.uk> writes: > >>On 22/03/2010 18:30, kj wrote: >>> Thanks! I'm glad to know that one can get the short circuiting using >>> a map-type idiom. (I prefer map over comprehensions when I don't need >>> to define a function just for the purpose of passing it to it.) > >>In what way does "map" over "comprehensions" save you defining a >>function? > >>any (map (is_invalid, L)) >>any (is_invalid (i) for i in L) > > I was talking in the *general* case. map at the very least requires a > lambda expression, which is a one-time function defintion.
But keep in mind that instead of this: map(lambda x,y: x+y, somelist) you can do this: import operator map(operator.add, somelist) In any case, the once-off cost of creating or importing a function is usually quite cheap. As usual, the best advise is not to worry about optimization until you have profiled the code and learned where the actual bottlenecks are. Write what reads best, not what you guess might be faster, until you really know you need the speed and that it is an optimization and not a pessimation. -- Steven -- http://mail.python.org/mailman/listinfo/python-list
