Dinesh B Vadhia wrote: > For some significant data pre-processing we have to perform the > following simple process: > > Is the integer x in a list of 13K sorted integers. That's it except > this has to be done >100m times with different x's (multiple times). > Yep, a real pain! > > I've put the 13K integers in a list S and am using the is 'x in S' function. > > I was wondering if there is anything faster?
Yes. Put the integers in a set and test for membership there. If for some reason the integers have to be in a list, and the list is sorted, use the bisect module to do a binary search, rather than the linear search used by 'x in S'. http://docs.python.org/lib/module-bisect.html Kent _______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor