Merged revisions 87032 via svnmerge from

svn+ssh://pythondev@svn.python.org/python/branches/py3k

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  r87032 | mark.dickinson | 2010-12-04 12:25:30 +0000 (Sat, 04 Dec 2010) | 3 lines

  Issue #10596: Fix float.__mod__ to have the same behaviour as
  float.__divmod__ with respect to signed zeros.
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This commit is contained in:
Mark Dickinson 2010-12-04 13:04:18 +00:00
parent 33154388f9
commit 0169af1534
3 changed files with 43 additions and 4 deletions

View file

@ -240,6 +240,31 @@ class GeneralFloatCases(unittest.TestCase):
self.assertTrue(s == s, "{%r} not equal to itself" % f)
self.assertTrue(d == d, "{%r : None} not equal to itself" % f)
def assertEqualAndEqualSign(self, a, b):
# fail unless a == b and a and b have the same sign bit;
# the only difference from assertEqual is that this test
# distingishes -0.0 and 0.0.
self.assertEqual((a, copysign(1.0, a)), (b, copysign(1.0, b)))
@requires_IEEE_754
def test_float_mod(self):
# Check behaviour of % operator for IEEE 754 special cases.
# In particular, check signs of zeros.
mod = operator.mod
self.assertEqualAndEqualSign(mod(-1.0, 1.0), 0.0)
self.assertEqualAndEqualSign(mod(-1e-100, 1.0), 1.0)
self.assertEqualAndEqualSign(mod(-0.0, 1.0), 0.0)
self.assertEqualAndEqualSign(mod(0.0, 1.0), 0.0)
self.assertEqualAndEqualSign(mod(1e-100, 1.0), 1e-100)
self.assertEqualAndEqualSign(mod(1.0, 1.0), 0.0)
self.assertEqualAndEqualSign(mod(-1.0, -1.0), -0.0)
self.assertEqualAndEqualSign(mod(-1e-100, -1.0), -1e-100)
self.assertEqualAndEqualSign(mod(-0.0, -1.0), -0.0)
self.assertEqualAndEqualSign(mod(0.0, -1.0), -0.0)
self.assertEqualAndEqualSign(mod(1e-100, -1.0), -1.0)
self.assertEqualAndEqualSign(mod(1.0, -1.0), -0.0)
class FormatFunctionsTestCase(unittest.TestCase):