On 15 September 2016 at 10:43, Raymond Hettinger <raymond.hettin...@gmail.com> wrote: > Something like this will reveal the true and massive improvement in iteration > speed: > > $ ./python.exe -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" > "list(d)"
>py -3.5 -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)" 10 loops, best of 3: 66.2 msec per loop >py -3.6 -m timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)" 10 loops, best of 3: 27.8 msec per loop And for Victor: >py -3.5 -m perf timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)" .................... Median +- std dev: 65.7 ms +- 3.8 ms >py -3.6 -m perf timeit -s "d=dict.fromkeys(map(str,range(10**6)))" "list(d)" .................... Median +- std dev: 27.9 ms +- 1.2 ms Just as a side point, perf provided essentially identical results but took 2 minutes as opposed to 8 seconds for timeit to do so. I understand why perf is better, and I appreciate all the work Victor did to create it, and analyze the results, but for getting a quick impression of how a microbenchmark performs, I don't see timeit as being *quite* as bad as Victor is claiming. I will tend to use perf now that I have it installed, and now that I know how to run a published timeit invocation using perf. It's a really cool tool. But I certainly won't object to seeing people publish timeit results (any more than I'd object to *any* mirobenchmark). Paul _______________________________________________ Python-Dev mailing list Python-Dev@python.org https://mail.python.org/mailman/listinfo/python-dev Unsubscribe: https://mail.python.org/mailman/options/python-dev/archive%40mail-archive.com
