John Posner <jjpos...@snet.net> wrote: > Do know what in the itertools implementation causes adding a 'if p <= > sqrt(n)' clause to *decrease* performance, while adding a > 'takewhile()' clause *increases* performance?
I haven't timed it, but I would guess that the takewhile was faster only because the sqrt(n) had been factored out of the loop. Try the original loop again precalculating the sqrt(n) and see how that compares. -- http://mail.python.org/mailman/listinfo/python-list