diff options
Diffstat (limited to 'Lib/test/test_float.py')
| -rw-r--r-- | Lib/test/test_float.py | 25 |
1 files changed, 25 insertions, 0 deletions
diff --git a/Lib/test/test_float.py b/Lib/test/test_float.py index b4897c98a9..b5b6b65859 100644 --- a/Lib/test/test_float.py +++ b/Lib/test/test_float.py @@ -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): |