Lib/test/test_unary.py

   1 """Test compiler changes for unary ops (+, -, ~) introduced in Python 2.2"""
   2
   3 import unittest
   4 from test.test_support import run_unittest, have_unicode
   5
   6 class UnaryOpTestCase(unittest.TestCase):
   7
   8     def test_negative(self):
   9         self.assertTrue(-2 == 0 - 2)
  10         self.assertTrue(-0 == 0)
  11         self.assertTrue(--2 == 2)
  12         self.assertTrue(-2L == 0 - 2L)
  13         self.assertTrue(-2.0 == 0 - 2.0)
  14         self.assertTrue(-2j == 0 - 2j)
  15
  16     def test_positive(self):
  17         self.assertTrue(+2 == 2)
  18         self.assertTrue(+0 == 0)
  19         self.assertTrue(++2 == 2)
  20         self.assertTrue(+2L == 2L)
  21         self.assertTrue(+2.0 == 2.0)
  22         self.assertTrue(+2j == 2j)
  23
  24     def test_invert(self):
  25         self.assertTrue(-2 == 0 - 2)
  26         self.assertTrue(-0 == 0)
  27         self.assertTrue(--2 == 2)
  28         self.assertTrue(-2L == 0 - 2L)
  29
  30     def test_no_overflow(self):
  31         nines = "9" * 32
  32         self.assertTrue(eval("+" + nines) == eval("+" + nines + "L"))
  33         self.assertTrue(eval("-" + nines) == eval("-" + nines + "L"))
  34         self.assertTrue(eval("~" + nines) == eval("~" + nines + "L"))
  35
  36     def test_negation_of_exponentiation(self):
  37         # Make sure '**' does the right thing; these form a
  38         # regression test for SourceForge bug #456756.
  39         self.assertEqual(-2 ** 3, -8)
  40         self.assertEqual((-2) ** 3, -8)
  41         self.assertEqual(-2 ** 4, -16)
  42         self.assertEqual((-2) ** 4, 16)
  43
  44     def test_bad_types(self):
  45         for op in '+', '-', '~':
  46             self.assertRaises(TypeError, eval, op + "'a'")
  47             if have_unicode:
  48                 self.assertRaises(TypeError, eval, op + "u'a'")
  49
  50         self.assertRaises(TypeError, eval, "~2j")
  51         self.assertRaises(TypeError, eval, "~2.0")
  52
  53
  54 def test_main():
  55     run_unittest(UnaryOpTestCase)
  56
  57
  58 if __name__ == "__main__":
  59     test_main()