diff options
Diffstat (limited to 'Lib')
| -rw-r--r-- | Lib/timeit.py | 28 |
1 files changed, 22 insertions, 6 deletions
diff --git a/Lib/timeit.py b/Lib/timeit.py index fd177cd..3d1f300 100644 --- a/Lib/timeit.py +++ b/Lib/timeit.py @@ -7,7 +7,7 @@ the Python Cookbook, published by O'Reilly. Library usage: see the Timer class. Command line usage: - python timeit.py [-n N] [-r N] [-s S] [-t] [-c] [statement] + python timeit.py [-n N] [-r N] [-s S] [-t] [-c] [-h] [statement] Options: -n/--number N: how many times to execute 'statement' (default: see below) @@ -15,6 +15,7 @@ Options: -s/--setup S: statements executed once before 'statement' (default 'pass') -t/--time: use time.time() (default on Unix) -c/--clock: use time.clock() (default on Windows) + -h/--help: print this usage message and exit statement: statement to be timed (default 'pass') A multi-line statement may be given by specifying each line as a @@ -33,11 +34,22 @@ 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. 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 (especially when comparing different versions of +Python). The baseline overhead is measured by invoking the program +without arguments. """ # To use this module with older versions of Python, the dependency on # the itertools module is easily removed; in the template, instead of -# itertools.repeat(None, count), use [None]*count. It's barely slower. +# itertools.repeat(None, number), use [None]*number. It's barely +# slower. Note: the baseline overhead, measured by the default +# invocation, differs for older 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. import sys import math @@ -141,11 +153,12 @@ def main(args=None): args = sys.argv[1:] import getopt try: - opts, args = getopt.getopt(args, "n:s:r:tc", + opts, args = getopt.getopt(args, "n:s:r:tch", ["number=", "setup=", "repeat=", - "time", "clock"]) + "time", "clock", "help"]) except getopt.error, err: print err + print "use -h/--help for command line help" return 2 timer = default_timer stmt = "\n".join(args) or "pass" @@ -161,10 +174,13 @@ def main(args=None): repeat = int(a) if repeat <= 0: repeat = 1 - if o in ("-t", "time"): + if o in ("-t", "--time"): timer = time.time - if o in ("-c", "clock"): + if o in ("-c", "--clock"): timer = time.clock + if o in ("-h", "--help"): + print __doc__, + return 0 t = Timer(stmt, setup, timer) if number == 0: # determine number so that 0.2 <= total time < 2.0 |