> >What's better is to get the length of the list where the value is true. > >how_many_evens = len( filter(lambda i, i%2==0, testlist) ) > > -Arcege As yet, I don't get the real difference between getting the length by filtering on i%2==0, and adding the 1s in reduce(add,[i%2==0 for i in testlist]). I'm missing some subtle point. Kirby