cpython/Lib/test/test_range.py

# Python test set -- built-in functions

import test.support, unittest
import sys
import pickle

import warnings
warnings.filterwarnings("ignore", "integer argument expected",
                        DeprecationWarning, "unittest")

class RangeTest(unittest.TestCase):
    def test_range(self):
        self.assertEqual(list(range(3)), [0, 1, 2])
        self.assertEqual(list(range(1, 5)), [1, 2, 3, 4])
        self.assertEqual(list(range(0)), [])
        self.assertEqual(list(range(-3)), [])
        self.assertEqual(list(range(1, 10, 3)), [1, 4, 7])
        self.assertEqual(list(range(5, -5, -3)), [5, 2, -1, -4])

        a = 10
        b = 100
        c = 50

        self.assertEqual(list(range(a, a+2)), [a, a+1])
        self.assertEqual(list(range(a+2, a, -1)), [a+2, a+1])
        self.assertEqual(list(range(a+4, a, -2)), [a+4, a+2])

        seq = list(range(a, b, c))
        self.assertTrue(a in seq)
        self.assertTrue(b not in seq)
        self.assertEqual(len(seq), 2)

        seq = list(range(b, a, -c))
        self.assertTrue(b in seq)
        self.assertTrue(a not in seq)
        self.assertEqual(len(seq), 2)

        seq = list(range(-a, -b, -c))
        self.assertTrue(-a in seq)
        self.assertTrue(-b not in seq)
        self.assertEqual(len(seq), 2)

        self.assertRaises(TypeError, range)
        self.assertRaises(TypeError, range, 1, 2, 3, 4)
        self.assertRaises(ValueError, range, 1, 2, 0)

        self.assertRaises(TypeError, range, 0.0, 2, 1)
        self.assertRaises(TypeError, range, 1, 2.0, 1)
        self.assertRaises(TypeError, range, 1, 2, 1.0)
        self.assertRaises(TypeError, range, 1e100, 1e101, 1e101)

        self.assertRaises(TypeError, range, 0, "spam")
        self.assertRaises(TypeError, range, 0, 42, "spam")

        self.assertEqual(len(range(0, sys.maxsize, sys.maxsize-1)), 2)

        r = range(-sys.maxsize, sys.maxsize, 2)
        self.assertEqual(len(r), sys.maxsize)

    def test_repr(self):
        self.assertEqual(repr(range(1)), 'range(0, 1)')
        self.assertEqual(repr(range(1, 2)), 'range(1, 2)')
        self.assertEqual(repr(range(1, 2, 3)), 'range(1, 2, 3)')

    def test_pickling(self):
        testcases = [(13,), (0, 11), (-22, 10), (20, 3, -1),
                     (13, 21, 3), (-2, 2, 2)]
        for proto in range(pickle.HIGHEST_PROTOCOL + 1):
            for t in testcases:
                r = range(*t)
                self.assertEquals(list(pickle.loads(pickle.dumps(r, proto))),
                                  list(r))

    def test_odd_bug(self):
        # This used to raise a "SystemError: NULL result without error"
        # because the range validation step was eating the exception
        # before NULL was returned.
        with self.assertRaises(TypeError):
            range([], 1, -1)

    def test_types(self):
        # Non-integer objects *equal* to any of the range's items are supposed
        # to be contained in the range.
        self.assertTrue(1.0 in range(3))
        self.assertTrue(True in range(3))
        self.assertTrue(1+0j in range(3))

        class C1:
            def __eq__(self, other): return True
        self.assertTrue(C1() in range(3))

        # Objects are never coerced into other types for comparison.
        class C2:
            def __int__(self): return 1
            def __index__(self): return 1
        self.assertFalse(C2() in range(3))
        # ..except if explicitly told so.
        self.assertTrue(int(C2()) in range(3))


    def test_strided_limits(self):
        r = range(0, 101, 2)
        self.assertTrue(0 in r)
        self.assertFalse(1 in r)
        self.assertTrue(2 in r)
        self.assertFalse(99 in r)
        self.assertTrue(100 in r)
        self.assertFalse(101 in r)

        r = range(0, -20, -1)
        self.assertTrue(0 in r)
        self.assertTrue(-1 in r)
        self.assertTrue(-19 in r)
        self.assertFalse(-20 in r)

        r = range(0, -20, -2)
        self.assertTrue(-18 in r)
        self.assertFalse(-19 in r)
        self.assertFalse(-20 in r)

    def test_empty(self):
        r = range(0)
        self.assertFalse(0 in r)
        self.assertFalse(1 in r)

        r = range(0, -10)
        self.assertFalse(0 in r)
        self.assertFalse(-1 in r)
        self.assertFalse(1 in r)

def test_main():
    test.support.run_unittest(RangeTest)

if __name__ == "__main__":
    test_main()