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Update timeit documentation w.r.t default timer changes.

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Georg Brandl 2012-05-01 11:59:36 +02:00
parent c9d77b2455
commit 67c1444454
1 changed files with 15 additions and 15 deletions
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30
Doc/library/timeit.rst
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@ -104,13 +104,7 @@ The module also defines three convenience functions:
.. 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`.
.. function:: repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000)
@ -149,13 +143,20 @@ 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
@ -173,12 +174,11 @@ 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::