Dick Moores wrote: > I DID have setup code, the "x=0". I now notice that if the "x=0" is > not stated as the setup code, the time difference is enormous, > 132-to-1 in this case. > > python -m timeit -s"x=0" "while x<100:" " x+=1" > 10000000 loops, best of 3: 0.116 usec per loop > > python -m timeit "x=0" "while x<100:" " x+=1" > 100000 loops, best of 3: 15.3 usec per loop
timeit runs the setup code once, then runs the timed code many times with the timer running. If "x=0" is outside the loop, then the while loop only runs once, because x == 100 after the first time through the loop. So your first version is effectively timing this: setup: x=100 timed code: while x<100: x+=1 which is of course a lot faster than actually running the loopp 100 times. Kent _______________________________________________ Tutor maillist - [email protected] http://mail.python.org/mailman/listinfo/tutor
