[Python-checkins] cpython (3.2): Issue #13478: document timeit.default_timer()

Tue Apr 24 18:14:00 CEST 2012

http://hg.python.org/cpython/rev/8165b59a4000
changeset: 76525:8165b59a4000
branch: 3.2
parent: 76522:01abffa8842a
user: Sandro Tosi <sandro.tosi at gmail.com>
date: Tue Apr 24 18:11:46 2012 +0200
summary:
 Issue #13478: document timeit.default_timer()
files:
 Doc/library/timeit.rst | 24 ++++++++++++++++--------
 1 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
--- a/Doc/library/timeit.rst
+++ b/Doc/library/timeit.rst
@@ -99,7 +99,19 @@
 timeit.Timer('for i in range(10): oct(i)', 'gc.enable()').timeit()
 
 
-The module also defines two convenience functions:
+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.
+
 
 .. function:: repeat(stmt='pass', setup='pass', timer=<default timer>, repeat=3, number=1000000)
 
@@ -161,13 +173,9 @@
 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.
 
-The default timer function is platform dependent. 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, the default timer functions measure wall clock time, not the CPU time.
-This means that other processes running on the same computer may interfere with
-the timing. The best thing to do when accurate timing is necessary is to repeat
+: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.
-- 
Repository URL: http://hg.python.org/cpython
