of datetime.datetime: microseconds are now rounded to nearest with ties going
to nearest even integer (ROUND_HALF_EVEN), instead of being rounding towards
zero (ROUND_DOWN). It's important that these methods use the same rounding
mode than datetime.timedelta to keep the property:
(datetime(1970,1,1) + timedelta(seconds=t)) == datetime.utcfromtimestamp(t)
It also the rounding mode used by round(float) for example.
Add more unit tests on the rounding mode in test_datetime.
datetime.datetime now round microseconds to nearest with ties going to nearest
even integer (ROUND_HALF_EVEN), as round(float), instead of rounding towards
-Infinity (ROUND_FLOOR).
pytime API: replace _PyTime_ROUND_HALF_UP with _PyTime_ROUND_HALF_EVEN. Fix
also _PyTime_Divide() for negative numbers.
_PyTime_AsTimeval_impl() now reuses _PyTime_Divide() instead of reimplementing
rounding modes.
"""Issue #23517: datetime.timedelta constructor now rounds microseconds to
nearest with ties going away from zero (ROUND_HALF_UP), as Python 2 and Python
older than 3.3, instead of rounding to nearest with ties going to nearest even
integer (ROUND_HALF_EVEN)."""
datetime.timedelta uses rounding mode ROUND_HALF_EVEN again.
datetime.datetime now round microseconds to nearest with ties going away from
zero (ROUND_HALF_UP), as Python 2 and Python older than 3.3, instead of
rounding towards -Infinity (ROUND_FLOOR).
with ties going away from zero (ROUND_HALF_UP), as Python 2 and Python older
than 3.3, instead of rounding to nearest with ties going to nearest even
integer (ROUND_HALF_EVEN).
I have compared output between pre- and post-patch runs of these tests
to make sure there's nothing missing and nothing broken, on both
Windows and Linux. The only differences I found were actually tests
that were previously *not* run.
This patch brings the pure-python datetime more in-line with the C
module. Patch contributed by Brian Kearns, a PyPy developer. PyPy
project has been running these modifications in PyPy2 stdlib.
This commit includes:
- General PEP8/cleanups;
- Better testing of argument types passed to constructors;
- Removal of duplicate operations;
- Optimization of timedelta creation;
- Caching the result of __hash__ like the C accelerator;
- Enhancements/bug fixes in tests.
time.ctime(), gmtime(), time.localtime(), datetime.date.fromtimestamp(),
datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp() now
raises an OverflowError, instead of a ValueError, if the timestamp does not fit
in time_t.
datetime.datetime.fromtimestamp() and datetime.datetime.utcfromtimestamp() now
round microseconds towards zero instead of rounding to nearest with ties going
away from zero.
Martin Panter
Alexander Belopolsky
Victor Stinner
Zachary Ware
Serhiy Storchaka
Antoine Pitrou
Raymond Hettinger
Benjamin Peterson
Ezio Melotti
Georg Brandl
Victor Stinner
Florent Xicluna
Eric Smith