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author | Terry Jan Reedy <tjreedy@udel.edu> | 2013-03-15 07:04:25 (GMT) |
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committer | Terry Jan Reedy <tjreedy@udel.edu> | 2013-03-15 07:04:25 (GMT) |
commit | d49af5dc2e77198e5e0e93cd9c2656012eaecfc7 (patch) | |
tree | 94bfbd181fcbbdfe39f7f17599346d69dc3ac556 /Lib/timeit.py | |
parent | e95f7c3d271465804b8a613a324d5b9fd6949e8a (diff) | |
download | cpython-d49af5dc2e77198e5e0e93cd9c2656012eaecfc7.zip cpython-d49af5dc2e77198e5e0e93cd9c2656012eaecfc7.tar.gz cpython-d49af5dc2e77198e5e0e93cd9c2656012eaecfc7.tar.bz2 |
Issue #17414: Add timeit, repeat, and default_timer to timeit.__all__.
Revise module docstring and update itertools import and use.
Diffstat (limited to 'Lib/timeit.py')
-rw-r--r-- | Lib/timeit.py | 46 |
1 files changed, 17 insertions, 29 deletions
diff --git a/Lib/timeit.py b/Lib/timeit.py index 4f7d28f..ead2030 100644 --- a/Lib/timeit.py +++ b/Lib/timeit.py @@ -31,38 +31,29 @@ treated similarly. If -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 difference in default timer function is because on Windows, -clock() has microsecond granularity but time()'s granularity is 1/60th -of a second; on Unix, clock() has 1/100th of a second granularity and -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 the timing a few times and use the best time. The -r option is -good for this; the default of 3 repetitions is probably enough in most -cases. On Unix, you can use clock() to measure CPU time. - Note: there is a certain baseline overhead associated with executing a -pass statement. The code here doesn't try to hide it, but you should -be aware of it. The baseline overhead can be measured by invoking the -program without arguments. - -The baseline overhead differs between Python versions! Also, to -fairly compare older Python versions to Python 2.3, you may want to -use python -O for the older versions to avoid timing SET_LINENO -instructions. +pass statement. It differs between versions. The code here doesn't try +to hide it, but you should be aware of it. The baseline overhead can be +measured by invoking the program without arguments. + +Classes: + + Timer + +Functions: + + timeit(string, string) -> float + repeat(string, string) -> list + default_timer() -> float + """ import gc import sys import time -try: - import itertools -except ImportError: - # Must be an older Python version (see timeit() below) - itertools = None +import itertools -__all__ = ["Timer"] +__all__ = ["Timer", "timeit", "repeat", "default_timer"] dummy_src_name = "<timeit-src>" default_number = 1000000 @@ -180,10 +171,7 @@ class Timer: to one million. The main statement, the setup statement and the timer function to be used are passed to the constructor. """ - if itertools: - it = itertools.repeat(None, number) - else: - it = [None] * number + it = itertools.repeat(None, number) gcold = gc.isenabled() gc.disable() try: |