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Diffstat (limited to 'lib/python2.7/timeit.py')
| -rw-r--r-- | lib/python2.7/timeit.py | 330 |
1 files changed, 0 insertions, 330 deletions
diff --git a/lib/python2.7/timeit.py b/lib/python2.7/timeit.py deleted file mode 100644 index da9e819..0000000 --- a/lib/python2.7/timeit.py +++ /dev/null @@ -1,330 +0,0 @@ -#! /usr/bin/env python - -"""Tool for measuring execution time of small code snippets. - -This module avoids a number of common traps for measuring execution -times. See also Tim Peters' introduction to the Algorithms chapter in -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] [-h] [--] [statement] - -Options: - -n/--number N: how many times to execute 'statement' (default: see below) - -r/--repeat N: how many times to repeat the timer (default 3) - -s/--setup S: statement to be executed once initially (default 'pass') - -t/--time: use time.time() (default on Unix) - -c/--clock: use time.clock() (default on Windows) - -v/--verbose: print raw timing results; repeat for more digits precision - -h/--help: print this usage message and exit - --: separate options from statement, use when statement starts with - - statement: statement to be timed (default 'pass') - -A multi-line statement may be given by specifying each line as a -separate argument; indented lines are possible by enclosing an -argument in quotes and using leading spaces. Multiple -s options are -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. -""" - -import gc -import sys -import time -try: - import itertools -except ImportError: - # Must be an older Python version (see timeit() below) - itertools = None - -__all__ = ["Timer"] - -dummy_src_name = "<timeit-src>" -default_number = 1000000 -default_repeat = 3 - -if sys.platform == "win32": - # On Windows, the best timer is time.clock() - default_timer = time.clock -else: - # On most other platforms the best timer is time.time() - default_timer = time.time - -# Don't change the indentation of the template; the reindent() calls -# in Timer.__init__() depend on setup being indented 4 spaces and stmt -# being indented 8 spaces. -template = """ -def inner(_it, _timer): - %(setup)s - _t0 = _timer() - for _i in _it: - %(stmt)s - _t1 = _timer() - return _t1 - _t0 -""" - -def reindent(src, indent): - """Helper to reindent a multi-line statement.""" - return src.replace("\n", "\n" + " "*indent) - -def _template_func(setup, func): - """Create a timer function. Used if the "statement" is a callable.""" - def inner(_it, _timer, _func=func): - setup() - _t0 = _timer() - for _i in _it: - _func() - _t1 = _timer() - return _t1 - _t0 - return inner - -class Timer: - """Class for timing execution speed of small code snippets. - - The constructor takes a statement to be timed, an additional - statement used for setup, and a timer function. Both statements - default to 'pass'; the timer function is platform-dependent (see - module doc string). - - To measure the execution time of the first statement, use the - timeit() method. The repeat() method is a convenience to call - timeit() multiple times and return a list of results. - - The statements may contain newlines, as long as they don't contain - multi-line string literals. - """ - - def __init__(self, stmt="pass", setup="pass", timer=default_timer): - """Constructor. See class doc string.""" - self.timer = timer - ns = {} - if isinstance(stmt, basestring): - stmt = reindent(stmt, 8) - if isinstance(setup, basestring): - setup = reindent(setup, 4) - src = template % {'stmt': stmt, 'setup': setup} - elif hasattr(setup, '__call__'): - src = template % {'stmt': stmt, 'setup': '_setup()'} - ns['_setup'] = setup - else: - raise ValueError("setup is neither a string nor callable") - self.src = src # Save for traceback display - code = compile(src, dummy_src_name, "exec") - exec code in globals(), ns - self.inner = ns["inner"] - elif hasattr(stmt, '__call__'): - self.src = None - if isinstance(setup, basestring): - _setup = setup - def setup(): - exec _setup in globals(), ns - elif not hasattr(setup, '__call__'): - raise ValueError("setup is neither a string nor callable") - self.inner = _template_func(setup, stmt) - else: - raise ValueError("stmt is neither a string nor callable") - - def print_exc(self, file=None): - """Helper to print a traceback from the timed code. - - Typical use: - - t = Timer(...) # outside the try/except - try: - t.timeit(...) # or t.repeat(...) - except: - t.print_exc() - - The advantage over the standard traceback is that source lines - in the compiled template will be displayed. - - The optional file argument directs where the traceback is - sent; it defaults to sys.stderr. - """ - import linecache, traceback - if self.src is not None: - linecache.cache[dummy_src_name] = (len(self.src), - None, - self.src.split("\n"), - dummy_src_name) - # else the source is already stored somewhere else - - traceback.print_exc(file=file) - - def timeit(self, number=default_number): - """Time 'number' executions of the main statement. - - To be precise, this executes the setup statement once, and - then returns the time it takes to execute the main statement - a number of times, as a float measured in seconds. The - argument is the number of times through the loop, defaulting - 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 - gcold = gc.isenabled() - gc.disable() - try: - timing = self.inner(it, self.timer) - finally: - if gcold: - gc.enable() - return timing - - def repeat(self, repeat=default_repeat, number=default_number): - """Call timeit() a few times. - - This is a convenience function that calls the timeit() - repeatedly, returning a list of results. The first argument - specifies how many times to call timeit(), defaulting to 3; - the second argument specifies the timer argument, defaulting - to one million. - - Note: it's tempting to calculate mean and standard deviation - from the result vector and report these. However, this is not - very useful. In a typical case, the lowest value gives a - lower bound for how fast your machine can run the given code - snippet; higher values in the result vector are typically not - caused by variability in Python's speed, but by other - processes interfering with your timing accuracy. So the min() - of the result is probably the only number you should be - interested in. After that, you should look at the entire - vector and apply common sense rather than statistics. - """ - r = [] - for i in range(repeat): - t = self.timeit(number) - r.append(t) - return r - -def timeit(stmt="pass", setup="pass", timer=default_timer, - number=default_number): - """Convenience function to create Timer object and call timeit method.""" - return Timer(stmt, setup, timer).timeit(number) - -def repeat(stmt="pass", setup="pass", timer=default_timer, - repeat=default_repeat, number=default_number): - """Convenience function to create Timer object and call repeat method.""" - return Timer(stmt, setup, timer).repeat(repeat, number) - -def main(args=None): - """Main program, used when run as a script. - - The optional argument specifies the command line to be parsed, - defaulting to sys.argv[1:]. - - The return value is an exit code to be passed to sys.exit(); it - may be None to indicate success. - - When an exception happens during timing, a traceback is printed to - stderr and the return value is 1. Exceptions at other times - (including the template compilation) are not caught. - """ - if args is None: - args = sys.argv[1:] - import getopt - try: - opts, args = getopt.getopt(args, "n:s:r:tcvh", - ["number=", "setup=", "repeat=", - "time", "clock", "verbose", "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" - number = 0 # auto-determine - setup = [] - repeat = default_repeat - verbose = 0 - precision = 3 - for o, a in opts: - if o in ("-n", "--number"): - number = int(a) - if o in ("-s", "--setup"): - setup.append(a) - if o in ("-r", "--repeat"): - repeat = int(a) - if repeat <= 0: - repeat = 1 - if o in ("-t", "--time"): - timer = time.time - if o in ("-c", "--clock"): - timer = time.clock - if o in ("-v", "--verbose"): - if verbose: - precision += 1 - verbose += 1 - if o in ("-h", "--help"): - print __doc__, - return 0 - setup = "\n".join(setup) or "pass" - # Include the current directory, so that local imports work (sys.path - # contains the directory of this script, rather than the current - # directory) - import os - sys.path.insert(0, os.curdir) - t = Timer(stmt, setup, timer) - if number == 0: - # determine number so that 0.2 <= total time < 2.0 - for i in range(1, 10): - number = 10**i - try: - x = t.timeit(number) - except: - t.print_exc() - return 1 - if verbose: - print "%d loops -> %.*g secs" % (number, precision, x) - if x >= 0.2: - break - try: - r = t.repeat(repeat, number) - except: - t.print_exc() - return 1 - best = min(r) - if verbose: - print "raw times:", " ".join(["%.*g" % (precision, x) for x in r]) - print "%d loops," % number, - usec = best * 1e6 / number - if usec < 1000: - print "best of %d: %.*g usec per loop" % (repeat, precision, usec) - else: - msec = usec / 1000 - if msec < 1000: - print "best of %d: %.*g msec per loop" % (repeat, precision, msec) - else: - sec = msec / 1000 - print "best of %d: %.*g sec per loop" % (repeat, precision, sec) - return None - -if __name__ == "__main__": - sys.exit(main()) |