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| -rw-r--r-- | Lib/test/test_complex.py | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/Lib/test/test_complex.py b/Lib/test/test_complex.py index a84e949..f28bb69 100644 --- a/Lib/test/test_complex.py +++ b/Lib/test/test_complex.py @@ -409,6 +409,25 @@ class ComplexTest(unittest.TestCase): @unittest.skipUnless(float.__getformat__("double").startswith("IEEE"), "test requires IEEE 754 doubles") + def test_negated_imaginary_literal(self): + z0 = -0j + z1 = -7j + z2 = -1e1000j + # This behaviour is actually incorrect: the real part of a negated + # imaginary literal should be -0.0, not 0.0. It's fixed in Python 3.2. + # However, the behaviour is already out in the wild in Python 2.x and + # Python <= 3.1.2, and it would be too disruptive to change it in a + # bugfix release, so we call it a 'feature' of Python 3.1, and test to + # ensure that the behaviour remains consistent across 3.1.x releases. + self.assertFloatsAreIdentical(z0.real, 0.0) + self.assertFloatsAreIdentical(z0.imag, -0.0) + self.assertFloatsAreIdentical(z1.real, 0.0) + self.assertFloatsAreIdentical(z1.imag, -7.0) + self.assertFloatsAreIdentical(z2.real, 0.0) + self.assertFloatsAreIdentical(z2.imag, -INF) + + @unittest.skipUnless(float.__getformat__("double").startswith("IEEE"), + "test requires IEEE 754 doubles") def test_overflow(self): self.assertEqual(complex("1e500"), complex(INF, 0.0)) self.assertEqual(complex("-1e500j"), complex(0.0, -INF)) |