STINNER Victor added the comment: Serhiy Storchaka: >> * autorange: start with 1 loop instead of 10 for slow benchmarks like >> time.sleep(1) > This is good if you run relatively slow benchmark, but it makes the result > less reliable. You always can specify -n1, but on your own risk.
Sorry, I don't understand how running 1 iteration instead of 10 makes the benchmark less reliable. IMO the reliability is more impacted by the number of repeatitions (-r). I changed the default from 3 to 5 repetitions, so timeit should be *more* reliable in Python 3.7 than 3.6. > Even "pass" takes at least 0.02 usec on my computer. What you want to measure > that takes < 1 ns? I think timeit is just wrong tool for this. It's just a matter of formatting. IMO clocks have a precision good enough to display nanoseconds when the benchmark uses many iterations (which is the case by default since autorange uses a minimum of 200 ms per benchmark). Before: $ python3.6 -m timeit 'pass' 100000000 loops, best of 3: 0.0339 usec per loop After: $ python3.7 -m timeit 'pass' 10000000 loops, best of 5: 33.9 nsec per loop IMO "33.9" is more readable than "0.0339". ---------- _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue28240> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
