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| author | Victor Stinner <victor.stinner@gmail.com> | 2015-09-18 14:42:05 +0200 |
|---|---|---|
| committer | Victor Stinner <victor.stinner@gmail.com> | 2015-09-18 14:42:05 +0200 |
| commit | 511491ade0bb77febb176bc75f049797f0c71ed0 (patch) | |
| tree | 1981db4c2c00eef86f32c03589174f98e46df857 /Lib/test/datetimetester.py | |
| parent | e3bcbd2bbade81a3591d69f607e1722c6016a489 (diff) | |
| download | cpython-git-511491ade0bb77febb176bc75f049797f0c71ed0.tar.gz | |
Issue #23517: Fix rounding in fromtimestamp() and utcfromtimestamp() methods
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.
Diffstat (limited to 'Lib/test/datetimetester.py')
| -rw-r--r-- | Lib/test/datetimetester.py | 24 |
1 files changed, 20 insertions, 4 deletions
diff --git a/Lib/test/datetimetester.py b/Lib/test/datetimetester.py index 8e48b9fd53..a942d4de81 100644 --- a/Lib/test/datetimetester.py +++ b/Lib/test/datetimetester.py @@ -650,8 +650,16 @@ class TestTimeDelta(HarmlessMixedComparison, unittest.TestCase): # Single-field rounding. eq(td(milliseconds=0.4/1000), td(0)) # rounds to 0 eq(td(milliseconds=-0.4/1000), td(0)) # rounds to 0 + eq(td(milliseconds=0.5/1000), td(microseconds=0)) + eq(td(milliseconds=-0.5/1000), td(microseconds=-0)) eq(td(milliseconds=0.6/1000), td(microseconds=1)) eq(td(milliseconds=-0.6/1000), td(microseconds=-1)) + eq(td(milliseconds=1.5/1000), td(microseconds=2)) + eq(td(milliseconds=-1.5/1000), td(microseconds=-2)) + eq(td(seconds=0.5/10**6), td(microseconds=0)) + eq(td(seconds=-0.5/10**6), td(microseconds=-0)) + eq(td(seconds=1/2**7), td(microseconds=7812)) + eq(td(seconds=-1/2**7), td(microseconds=-7812)) # Rounding due to contributions from more than one field. us_per_hour = 3600e6 @@ -1824,12 +1832,14 @@ class TestDateTime(TestDate): tzinfo=timezone(timedelta(hours=-5), 'EST')) self.assertEqual(t.timestamp(), 18000 + 3600 + 2*60 + 3 + 4*1e-6) + def test_microsecond_rounding(self): for fts in [self.theclass.fromtimestamp, self.theclass.utcfromtimestamp]: zero = fts(0) self.assertEqual(zero.second, 0) self.assertEqual(zero.microsecond, 0) + one = fts(1e-6) try: minus_one = fts(-1e-6) except OSError: @@ -1840,22 +1850,28 @@ class TestDateTime(TestDate): self.assertEqual(minus_one.microsecond, 999999) t = fts(-1e-8) - self.assertEqual(t, minus_one) + self.assertEqual(t, zero) t = fts(-9e-7) self.assertEqual(t, minus_one) t = fts(-1e-7) - self.assertEqual(t, minus_one) + self.assertEqual(t, zero) + t = fts(-1/2**7) + self.assertEqual(t.second, 59) + self.assertEqual(t.microsecond, 992188) t = fts(1e-7) self.assertEqual(t, zero) t = fts(9e-7) - self.assertEqual(t, zero) + self.assertEqual(t, one) t = fts(0.99999949) self.assertEqual(t.second, 0) self.assertEqual(t.microsecond, 999999) t = fts(0.9999999) + self.assertEqual(t.second, 1) + self.assertEqual(t.microsecond, 0) + t = fts(1/2**7) self.assertEqual(t.second, 0) - self.assertEqual(t.microsecond, 999999) + self.assertEqual(t.microsecond, 7812) def test_insane_fromtimestamp(self): # It's possible that some platform maps time_t to double, |