https://github.com/python/cpython/commit/f3b74d62698d5f0ee7dd905b8a7b9189e6ef9fce commit: f3b74d62698d5f0ee7dd905b8a7b9189e6ef9fce branch: main author: Miikka Koskinen <[email protected]> committer: hugovk <[email protected]> date: 2026-04-03T06:47:21Z summary:
gh-80642: timeit - make target time of autorange configurable (#140283) Co-authored-by: Alessandro Cucci <[email protected]> Co-authored-by: blurb-it[bot] <blurb-it[bot]@users.noreply.github.com> Co-authored-by: Hugo van Kemenade <[email protected]> Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Stan Ulbrych <[email protected]> Co-authored-by: Bénédikt Tran <[email protected]> files: A Misc/NEWS.d/next/Library/2019-04-25-21-11-37.bpo-36461.TO5YyP.rst M Doc/library/timeit.rst M Doc/whatsnew/3.15.rst M Lib/test/test_timeit.py M Lib/timeit.py diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst index bc12061a2aeb2d..aed7e7556f6666 100644 --- a/Doc/library/timeit.rst +++ b/Doc/library/timeit.rst @@ -143,21 +143,24 @@ The module defines three convenience functions and a public class: timeit.Timer('for i in range(10): oct(i)', 'gc.enable()').timeit() - .. method:: Timer.autorange(callback=None) + .. method:: Timer.autorange(callback=None, target_time=None) Automatically determine how many times to call :meth:`.timeit`. This is a convenience function that calls :meth:`.timeit` repeatedly - so that the total time >= 0.2 second, returning the eventual + so that the total time >= *Timer.target_time* seconds, returning the eventual (number of loops, time taken for that number of loops). It calls :meth:`.timeit` with increasing numbers from the sequence 1, 2, 5, - 10, 20, 50, ... until the time taken is at least 0.2 seconds. + 10, 20, 50, ... until the time taken is at least *target_time* seconds. If *callback* is given and is not ``None``, it will be called after each trial with two arguments: ``callback(number, time_taken)``. .. versionadded:: 3.6 + .. versionchanged:: next + The optional *target_time* parameter was added. + .. method:: Timer.repeat(repeat=5, number=1000000) @@ -239,6 +242,13 @@ Where the following options are understood: .. versionadded:: 3.5 +.. option:: -t, --target-time=T + + if :option:`--number` is 0, the code will run until it takes at + least this many seconds (default: 0.2) + + .. versionadded:: next + .. option:: -v, --verbose print raw timing results; repeat for more digits precision @@ -254,7 +264,7 @@ similarly. If :option:`-n` is not given, a suitable number of loops is calculated by trying increasing numbers from the sequence 1, 2, 5, 10, 20, 50, ... until the total -time is at least 0.2 seconds. +time is at least :option:`--target-time` seconds (default: 0.2). :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 diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst index 2a5f9c939e7280..287109035f1ee6 100644 --- a/Doc/whatsnew/3.15.rst +++ b/Doc/whatsnew/3.15.rst @@ -1090,6 +1090,11 @@ timeit :ref:`environment variables <using-on-controlling-color>`. (Contributed by Yi Hong in :gh:`139374`.) +* Make the target time of :meth:`timeit.Timer.autorange` configurable + and add ``--target-time`` option to the command-line interface. + (Contributed by Alessandro Cucci and Miikka Koskinen in :gh:`140283`.) + + tkinter ------- diff --git a/Lib/test/test_timeit.py b/Lib/test/test_timeit.py index f8bc306b455a5d..8837e88ba638cf 100644 --- a/Lib/test/test_timeit.py +++ b/Lib/test/test_timeit.py @@ -364,10 +364,10 @@ def test_main_exception_fixed_reps(self): s = self.run_main(switches=['-n1', '1/0']) self.assert_exc_string(error_stringio.getvalue(), 'ZeroDivisionError') - def autorange(self, seconds_per_increment=1/1024, callback=None): + def autorange(self, seconds_per_increment=1/1024, callback=None, target_time=0.2): timer = FakeTimer(seconds_per_increment=seconds_per_increment) t = timeit.Timer(stmt=self.fake_stmt, setup=self.fake_setup, timer=timer) - return t.autorange(callback) + return t.autorange(callback, target_time=target_time) def test_autorange(self): num_loops, time_taken = self.autorange() @@ -379,6 +379,11 @@ def test_autorange_second(self): self.assertEqual(num_loops, 1) self.assertEqual(time_taken, 1.0) + def test_autorange_with_target_time(self): + num_loops, time_taken = self.autorange(target_time=1.0) + self.assertEqual(num_loops, 2000) + self.assertEqual(time_taken, 2000/1024) + def test_autorange_with_callback(self): def callback(a, b): print("{} {:.3f}".format(a, b)) diff --git a/Lib/timeit.py b/Lib/timeit.py index 80791acdeca23f..f900da6ffe7d67 100644 --- a/Lib/timeit.py +++ b/Lib/timeit.py @@ -7,7 +7,7 @@ Library usage: see the Timer class. Command line usage: - python timeit.py [-n N] [-r N] [-s S] [-p] [-h] [--] [statement] + python timeit.py [-n N] [-r N] [-s S] [-p] [-h] [-t T] [--] [statement] Options: -n/--number N: how many times to execute 'statement' (default: see below) @@ -17,6 +17,9 @@ -p/--process: use time.process_time() (default is time.perf_counter()) -v/--verbose: print raw timing results; repeat for more digits precision -u/--unit: set the output time unit (nsec, usec, msec, or sec) + -t/--target-time T: if --number is 0 the code will run until it + takes *at least* this many seconds + (default: 0.2) -h/--help: print this usage message and exit --: separate options from statement, use when statement starts with - statement: statement to be timed (default 'pass') @@ -28,7 +31,7 @@ If -n is not given, a suitable number of loops is calculated by trying increasing numbers from the sequence 1, 2, 5, 10, 20, 50, ... until the -total time is at least 0.2 seconds. +total time is at least --target-time seconds. Note: there is a certain baseline overhead associated with executing a pass statement. It differs between versions. The code here doesn't try @@ -57,6 +60,7 @@ default_number = 1000000 default_repeat = 5 default_timer = time.perf_counter +default_target_time = 0.2 _globals = globals @@ -212,12 +216,13 @@ def repeat(self, repeat=default_repeat, number=default_number): r.append(t) return r - def autorange(self, callback=None): - """Return the number of loops and time taken so that total time >= 0.2. + def autorange(self, callback=None, target_time=default_target_time): + """Return the number of loops and time taken so that + total time >= target_time (default is 0.2 seconds). Calls the timeit method with increasing numbers from the sequence - 1, 2, 5, 10, 20, 50, ... until the time taken is at least 0.2 - second. Returns (number, time_taken). + 1, 2, 5, 10, 20, 50, ... until the target time is reached. + Returns (number, time_taken). If *callback* is given and is not None, it will be called after each trial with two arguments: ``callback(number, time_taken)``. @@ -229,7 +234,7 @@ def autorange(self, callback=None): time_taken = self.timeit(number) if callback: callback(number, time_taken) - if time_taken >= 0.2: + if time_taken >= target_time: return (number, time_taken) i *= 10 @@ -270,9 +275,10 @@ def main(args=None, *, _wrap_timer=None): colorize = _colorize.can_colorize() try: - opts, args = getopt.getopt(args, "n:u:s:r:pvh", + opts, args = getopt.getopt(args, "n:u:s:r:pt:vh", ["number=", "setup=", "repeat=", - "process", "verbose", "unit=", "help"]) + "process", "target-time=", + "verbose", "unit=", "help"]) except getopt.error as err: print(err) print("use -h/--help for command line help") @@ -281,6 +287,7 @@ def main(args=None, *, _wrap_timer=None): timer = default_timer stmt = "\n".join(args) or "pass" number = 0 # auto-determine + target_time = default_target_time setup = [] repeat = default_repeat verbose = 0 @@ -305,6 +312,8 @@ def main(args=None, *, _wrap_timer=None): repeat = 1 if o in ("-p", "--process"): timer = time.process_time + if o in ("-t", "--target-time"): + target_time = float(a) if o in ("-v", "--verbose"): if verbose: precision += 1 @@ -324,7 +333,7 @@ def main(args=None, *, _wrap_timer=None): t = Timer(stmt, setup, timer) if number == 0: - # determine number so that 0.2 <= total time < 2.0 + # determine number so that total time >= target_time callback = None if verbose: def callback(number, time_taken): @@ -333,7 +342,7 @@ def callback(number, time_taken): print(msg.format(num=number, s='s' if plural else '', secs=time_taken, prec=precision)) try: - number, _ = t.autorange(callback) + number, _ = t.autorange(callback, target_time) except: t.print_exc(colorize=colorize) return 1 diff --git a/Misc/NEWS.d/next/Library/2019-04-25-21-11-37.bpo-36461.TO5YyP.rst b/Misc/NEWS.d/next/Library/2019-04-25-21-11-37.bpo-36461.TO5YyP.rst new file mode 100644 index 00000000000000..e78f66018077c2 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-04-25-21-11-37.bpo-36461.TO5YyP.rst @@ -0,0 +1,3 @@ +Make the target time of :meth:`timeit.Timer.autorange` configurable +and add ``--target-time`` option to the command-line interface of +:mod:`timeit`. _______________________________________________ Python-checkins mailing list -- [email protected] To unsubscribe send an email to [email protected] https://mail.python.org/mailman3//lists/python-checkins.python.org Member address: [email protected]
