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Tests for Python 3.1's treatment of negated imaginary literals.

This commit is contained in:
Mark Dickinson 2010-06-30 10:55:51 +00:00
parent ce5b6c43bf
commit bf9f79b185
1 changed files with 19 additions and 0 deletions
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19
Lib/test/test_complex.py
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@ -407,6 +407,25 @@ class ComplexTest(unittest.TestCase):
self.assertEquals(atan2(z1.imag, -1.), atan2(0., -1.))
self.assertEquals(atan2(z2.imag, -1.), atan2(-0., -1.))
@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):