[Python-checkins] cpython: Issue #28469: timeit now uses the sequence 1, 2, 5, 10, 20, 50,... instead
serhiy.storchaka
python-checkins at python.org
Sun Oct 23 08:17:58 EDT 2016
https://hg.python.org/cpython/rev/8e6cc952adc6
changeset: 104658:8e6cc952adc6
user: Serhiy Storchaka <storchaka at gmail.com>
date: Sun Oct 23 15:17:05 2016 +0300
summary:
Issue #28469: timeit now uses the sequence 1, 2, 5, 10, 20, 50,... instead
of 1, 10, 100,... for autoranging.
files:
Doc/library/timeit.rst | 23 +++++-----
Lib/test/test_timeit.py | 59 +++++++++++++++++-----------
Lib/timeit.py | 25 ++++++-----
Misc/NEWS | 3 +
4 files changed, 63 insertions(+), 47 deletions(-)
diff --git a/Doc/library/timeit.rst b/Doc/library/timeit.rst
--- a/Doc/library/timeit.rst
+++ b/Doc/library/timeit.rst
@@ -28,11 +28,11 @@
.. code-block:: sh
$ python3 -m timeit '"-".join(str(n) for n in range(100))'
- 10000 loops, best of 3: 30.2 usec per loop
+ 10000 loops, best of 5: 30.2 usec per loop
$ python3 -m timeit '"-".join([str(n) for n in range(100)])'
- 10000 loops, best of 3: 27.5 usec per loop
+ 10000 loops, best of 5: 27.5 usec per loop
$ python3 -m timeit '"-".join(map(str, range(100)))'
- 10000 loops, best of 3: 23.2 usec per loop
+ 10000 loops, best of 5: 23.2 usec per loop
This can be achieved from the :ref:`python-interface` with::
@@ -141,9 +141,8 @@
This is a convenience function that calls :meth:`.timeit` repeatedly
so that the total time >= 0.2 second, returning the eventual
(number of loops, time taken for that number of loops). It calls
- :meth:`.timeit` with *number* set to successive powers of ten (10,
- 100, 1000, ...) up to a maximum of one billion, until the time taken
- is at least 0.2 second, or the maximum is reached.
+ :meth:`.timeit` with increasing numbers from the sequence 1, 2, 5,
+ 10, 20, 50, ... until the time taken is at least 0.2 second.
If *callback* is given and is not ``None``, it will be called after
each trial with two arguments: ``callback(number, time_taken)``.
@@ -268,9 +267,9 @@
.. code-block:: sh
$ python -m timeit -s 'text = "sample string"; char = "g"' 'char in text'
- 10000000 loops, best of 3: 0.0877 usec per loop
+ 5000000 loops, best of 5: 0.0877 usec per loop
$ python -m timeit -s 'text = "sample string"; char = "g"' 'text.find(char)'
- 1000000 loops, best of 3: 0.342 usec per loop
+ 1000000 loops, best of 5: 0.342 usec per loop
::
@@ -297,14 +296,14 @@
.. code-block:: sh
$ python -m timeit 'try:' ' str.__bool__' 'except AttributeError:' ' pass'
- 100000 loops, best of 3: 15.7 usec per loop
+ 20000 loops, best of 5: 15.7 usec per loop
$ python -m timeit 'if hasattr(str, "__bool__"): pass'
- 100000 loops, best of 3: 4.26 usec per loop
+ 50000 loops, best of 5: 4.26 usec per loop
$ python -m timeit 'try:' ' int.__bool__' 'except AttributeError:' ' pass'
- 1000000 loops, best of 3: 1.43 usec per loop
+ 200000 loops, best of 5: 1.43 usec per loop
$ python -m timeit 'if hasattr(int, "__bool__"): pass'
- 100000 loops, best of 3: 2.23 usec per loop
+ 100000 loops, best of 5: 2.23 usec per loop
::
diff --git a/Lib/test/test_timeit.py b/Lib/test/test_timeit.py
--- a/Lib/test/test_timeit.py
+++ b/Lib/test/test_timeit.py
@@ -256,7 +256,7 @@
def test_main_milliseconds(self):
s = self.run_main(seconds_per_increment=0.0055)
- self.assertEqual(s, "100 loops, best of 5: 5.5 msec per loop\n")
+ self.assertEqual(s, "50 loops, best of 5: 5.5 msec per loop\n")
def test_main_microseconds(self):
s = self.run_main(seconds_per_increment=0.0000025, switches=['-n100'])
@@ -304,35 +304,43 @@
"""))
def test_main_very_verbose(self):
- s = self.run_main(seconds_per_increment=0.000050, switches=['-vv'])
+ s = self.run_main(seconds_per_increment=0.000_030, switches=['-vv'])
self.assertEqual(s, dedent("""\
- 1 loop -> 5e-05 secs
- 10 loops -> 0.0005 secs
- 100 loops -> 0.005 secs
- 1000 loops -> 0.05 secs
- 10000 loops -> 0.5 secs
+ 1 loop -> 3e-05 secs
+ 2 loops -> 6e-05 secs
+ 5 loops -> 0.00015 secs
+ 10 loops -> 0.0003 secs
+ 20 loops -> 0.0006 secs
+ 50 loops -> 0.0015 secs
+ 100 loops -> 0.003 secs
+ 200 loops -> 0.006 secs
+ 500 loops -> 0.015 secs
+ 1000 loops -> 0.03 secs
+ 2000 loops -> 0.06 secs
+ 5000 loops -> 0.15 secs
+ 10000 loops -> 0.3 secs
- raw times: 500 msec, 500 msec, 500 msec, 500 msec, 500 msec
+ raw times: 300 msec, 300 msec, 300 msec, 300 msec, 300 msec
- 10000 loops, best of 5: 50 usec per loop
+ 10000 loops, best of 5: 30 usec per loop
"""))
def test_main_with_time_unit(self):
- unit_sec = self.run_main(seconds_per_increment=0.002,
+ unit_sec = self.run_main(seconds_per_increment=0.003,
switches=['-u', 'sec'])
self.assertEqual(unit_sec,
- "100 loops, best of 5: 0.002 sec per loop\n")
- unit_msec = self.run_main(seconds_per_increment=0.002,
+ "100 loops, best of 5: 0.003 sec per loop\n")
+ unit_msec = self.run_main(seconds_per_increment=0.003,
switches=['-u', 'msec'])
self.assertEqual(unit_msec,
- "100 loops, best of 5: 2 msec per loop\n")
- unit_usec = self.run_main(seconds_per_increment=0.002,
+ "100 loops, best of 5: 3 msec per loop\n")
+ unit_usec = self.run_main(seconds_per_increment=0.003,
switches=['-u', 'usec'])
self.assertEqual(unit_usec,
- "100 loops, best of 5: 2e+03 usec per loop\n")
+ "100 loops, best of 5: 3e+03 usec per loop\n")
# Test invalid unit input
with captured_stderr() as error_stringio:
- invalid = self.run_main(seconds_per_increment=0.002,
+ invalid = self.run_main(seconds_per_increment=0.003,
switches=['-u', 'parsec'])
self.assertEqual(error_stringio.getvalue(),
"Unrecognized unit. Please select nsec, usec, msec, or sec.\n")
@@ -347,15 +355,15 @@
s = self.run_main(switches=['-n1', '1/0'])
self.assert_exc_string(error_stringio.getvalue(), 'ZeroDivisionError')
- def autorange(self, seconds_per_increment=0.001, callback=None):
+ def autorange(self, seconds_per_increment=1/1024, callback=None):
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)
def test_autorange(self):
num_loops, time_taken = self.autorange()
- self.assertEqual(num_loops, 1000)
- self.assertEqual(time_taken, 1.0)
+ self.assertEqual(num_loops, 500)
+ self.assertEqual(time_taken, 500/1024)
def test_autorange_second(self):
num_loops, time_taken = self.autorange(seconds_per_increment=1.0)
@@ -367,12 +375,17 @@
print("{} {:.3f}".format(a, b))
with captured_stdout() as s:
num_loops, time_taken = self.autorange(callback=callback)
- self.assertEqual(num_loops, 1000)
- self.assertEqual(time_taken, 1.0)
+ self.assertEqual(num_loops, 500)
+ self.assertEqual(time_taken, 500/1024)
expected = ('1 0.001\n'
+ '2 0.002\n'
+ '5 0.005\n'
'10 0.010\n'
- '100 0.100\n'
- '1000 1.000\n')
+ '20 0.020\n'
+ '50 0.049\n'
+ '100 0.098\n'
+ '200 0.195\n'
+ '500 0.488\n')
self.assertEqual(s.getvalue(), expected)
diff --git a/Lib/timeit.py b/Lib/timeit.py
--- a/Lib/timeit.py
+++ b/Lib/timeit.py
@@ -208,22 +208,23 @@
def autorange(self, callback=None):
"""Return the number of loops so that total time >= 0.2.
- Calls the timeit method with *number* set to successive powers of
- ten (10, 100, 1000, ...) up to a maximum of one billion, until
- the time taken is at least 0.2 second, or the maximum is reached.
- Returns ``(number, time_taken)``.
+ 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).
If *callback* is given and is not None, it will be called after
each trial with two arguments: ``callback(number, time_taken)``.
"""
- for i in range(0, 10):
- number = 10**i
- time_taken = self.timeit(number)
- if callback:
- callback(number, time_taken)
- if time_taken >= 0.2:
- break
- return (number, time_taken)
+ i = 1
+ while True:
+ for j in 1, 2, 5:
+ number = i * j
+ time_taken = self.timeit(number)
+ if callback:
+ callback(number, time_taken)
+ if time_taken >= 0.2:
+ return (number, time_taken)
+ i *= 10
def timeit(stmt="pass", setup="pass", timer=default_timer,
number=default_number, globals=None):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -97,6 +97,9 @@
Library
-------
+- Issue #28469: timeit now uses the sequence 1, 2, 5, 10, 20, 50,... instead
+ of 1, 10, 100,... for autoranging.
+
- Issue #28115: Command-line interface of the zipfile module now uses argparse.
Added support of long options.
--
Repository URL: https://hg.python.org/cpython
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