/Lib/test/test_unary.py

 1"""Test compiler changes for unary ops (+, -, ~) introduced in Python 2.2"""
 2
 3import unittest
 4from test.test_support import run_unittest, have_unicode
 5
 6class UnaryOpTestCase(unittest.TestCase):
 7
 8    def test_negative(self):
 9        self.assert_(-2 == 0 - 2)
10        self.assert_(-0 == 0)
11        self.assert_(--2 == 2)
12        self.assert_(-2L == 0 - 2L)
13        self.assert_(-2.0 == 0 - 2.0)
14        self.assert_(-2j == 0 - 2j)
15
16    def test_positive(self):
17        self.assert_(+2 == 2)
18        self.assert_(+0 == 0)
19        self.assert_(++2 == 2)
20        self.assert_(+2L == 2L)
21        self.assert_(+2.0 == 2.0)
22        self.assert_(+2j == 2j)
23
24    def test_invert(self):
25        self.assert_(-2 == 0 - 2)
26        self.assert_(-0 == 0)
27        self.assert_(--2 == 2)
28        self.assert_(-2L == 0 - 2L)
29
30    def test_no_overflow(self):
31        nines = "9" * 32
32        self.assert_(eval("+" + nines) == eval("+" + nines + "L"))
33        self.assert_(eval("-" + nines) == eval("-" + nines + "L"))
34        self.assert_(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
54def test_main():
55    run_unittest(UnaryOpTestCase)
56
57
58if __name__ == "__main__":
59    test_main()