Paul Rubin: > print x, sum(1 for _ in g) Don't use that, use my function :-) If g has a __len__ you are wasting time. And sum(1 ...) is (on my PC) slower. J. Clifford Dyer: > if __name__ == '__main__': > test_func(summer, 10000000) > test_func(tupler, 10000000) > test_func(summer, 100000000) > test_func(tupler, 100000000) Have you forgotten my function? Bye, bearophile