diff options
Diffstat (limited to 'Doc/library/timeit.rst')
| -rw-r--r-- | Doc/library/timeit.rst | 33 |
1 files changed, 18 insertions, 15 deletions
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst index a3ec66f..a487917 100644 --- a/Doc/library/timeit.rst +++ b/Doc/library/timeit.rst @@ -73,13 +73,10 @@ The module defines three convenience functions and a public class: .. function:: default_timer() - Define a default timer, in a platform-specific manner. On Windows, - :func:`time.clock` has microsecond granularity, but :func:`time.time`'s - granularity is 1/60th of a second. On Unix, :func:`time.clock` has 1/100th of - a second granularity, and :func:`time.time` is much more precise. On either - platform, :func:`default_timer` measures wall clock time, not the CPU - time. This means that other processes running on the same computer may - interfere with the timing. + The default timer, which is always :func:`time.perf_counter`. + + .. versionchanged:: 3.3 + :func:`time.perf_counter` is now the default timer. .. class:: Timer(stmt='pass', setup='pass', timer=<timer function>) @@ -187,13 +184,20 @@ Where the following options are understood: statement to be executed once initially (default ``pass``) +.. cmdoption:: -p, --process + + measure process time, not wallclock time, using :func:`time.process_time` + instead of :func:`time.perf_counter`, which is the default + + .. versionadded:: 3.3 + .. cmdoption:: -t, --time - use :func:`time.time` (default on all platforms but Windows) + use :func:`time.time` (deprecated) .. cmdoption:: -c, --clock - use :func:`time.clock` (default on Windows) + use :func:`time.clock` (deprecated) .. cmdoption:: -v, --verbose @@ -211,12 +215,11 @@ similarly. If :option:`-n` is not given, a suitable number of loops is calculated by trying successive powers of 10 until the total time is at least 0.2 seconds. -:func:`default_timer` measurations can be affected by other programs running on -the same machine, so -the best thing to do when accurate timing is necessary is to repeat -the timing a few times and use the best time. The :option:`-r` option is good -for this; the default of 3 repetitions is probably enough in most cases. On -Unix, you can use :func:`time.clock` to measure CPU time. +:func:`default_timer` measurements can be affected by other programs running on +the same machine, so the best thing to do when accurate timing is necessary is +to repeat the timing a few times and use the best time. The :option:`-r` +option is good for this; the default of 3 repetitions is probably enough in +most cases. You can use :func:`time.process_time` to measure CPU time. .. note:: |