text: # -*- coding: utf-8 -*-
  """
  Tests for the backported class:`range` class.
  """
  
  from future.builtins import range
  from future.tests.base import unittest
  
  from collections import Iterator, Sequence
  from operator import attrgetter
  
  
  class RangeTests(unittest.TestCase):
      def test_range(self):
          self.assertTrue(isinstance(range(0), Sequence))
          self.assertTrue(isinstance(reversed(range(0)), Iterator))
  
      def test_bool_range(self):
          self.assertFalse(range(0))
          self.assertTrue(range(1))
          self.assertFalse(range(1, 1))
          self.assertFalse(range(5, 2))
  
      def test_equality_range(self):
          self.assertEqual(range(7), range(7))
          self.assertEqual(range(0), range(1, 1))
          self.assertEqual(range(0, 10, 3), range(0, 11, 3))
  
      def test_contains(self):
          self.assertIn(1, range(2))
          self.assertNotIn(10, range(2))
          self.assertNotIn(None, range(2))
          self.assertNotIn("", range(2))
  
      # Use strict equality of attributes when slicing to catch subtle differences
      def assertRangesEqual(self, r1, r2):
          by_attrs = attrgetter('start', 'stop', 'step')
          self.assertEqual(by_attrs(r1), by_attrs(r2))
  
      def test_slice_empty_range(self):
          self.assertRangesEqual(range(0)[:], range(0))
          self.assertRangesEqual(range(0)[::-1], range(-1, -1, -1))
  
      def test_slice_overflow_range(self):
          r = range(8)
          self.assertRangesEqual(r[2:200], range(2, 8))
          self.assertRangesEqual(r[-200:-2], range(0, 6))
  
      def test_slice_range(self):
          r = range(-8, 8)
          self.assertRangesEqual(r[:], range(-8, 8))
          self.assertRangesEqual(r[:2], range(-8, -6))
          self.assertRangesEqual(r[:-2], range(-8, 6))
          self.assertRangesEqual(r[2:], range(-6, 8))
          self.assertRangesEqual(r[-2:], range(6, 8))
          self.assertRangesEqual(r[2:-2], range(-6, 6))
  
      def test_rev_slice_range(self):
          r = range(-8, 8)
          self.assertRangesEqual(r[::-1], range(7, -9, -1))
          self.assertRangesEqual(r[:2:-1], range(7, -6, -1))
          self.assertRangesEqual(r[:-2:-1], range(7, 6, -1))
          self.assertRangesEqual(r[2::-1], range(-6, -9, -1))
          self.assertRangesEqual(r[-2::-1], range(6, -9, -1))
          self.assertRangesEqual(r[-2:2:-1], range(6, -6, -1))
  
      def test_slice_rev_range(self):
          r = range(8, -8, -1)
          self.assertRangesEqual(r[:], range(8, -8, -1))
          self.assertRangesEqual(r[:2], range(8, 6, -1))
          self.assertRangesEqual(r[:-2], range(8, -6, -1))
          self.assertRangesEqual(r[2:], range(6, -8, -1))
          self.assertRangesEqual(r[-2:], range(-6, -8, -1))
          self.assertRangesEqual(r[2:-2], range(6, -6, -1))
  
      def test_rev_slice_rev_range(self):
          r = range(8, -8, -1)
          self.assertRangesEqual(r[::-1], range(-7, 9))
          self.assertRangesEqual(r[:2:-1], range(-7, 6))
          self.assertRangesEqual(r[:-2:-1], range(-7, -6))
          self.assertRangesEqual(r[2::-1], range(6, 9))
          self.assertRangesEqual(r[-2::-1], range(-6, 9))
          self.assertRangesEqual(r[-2:2:-1], range(-6, 6))
  
      def test_stepped_slice_range(self):
          r = range(-8, 8)
          self.assertRangesEqual(r[::2], range(-8, 8, 2))
          self.assertRangesEqual(r[:2:2], range(-8, -6, 2))
          self.assertRangesEqual(r[:-2:2], range(-8, 6, 2))
          self.assertRangesEqual(r[2::2], range(-6, 8, 2))
          self.assertRangesEqual(r[-2::2], range(6, 8, 2))
          self.assertRangesEqual(r[2:-2:2], range(-6, 6, 2))
  
      def test_rev_stepped_slice_range(self):
          r = range(-8, 8)
          self.assertRangesEqual(r[::-2], range(7, -9, -2))
          self.assertRangesEqual(r[:2:-2], range(7, -6, -2))
          self.assertRangesEqual(r[:-2:-2], range(7, 6, -2))
          self.assertRangesEqual(r[2::-2], range(-6, -9, -2))
          self.assertRangesEqual(r[-2::-2], range(6, -9, -2))
          self.assertRangesEqual(r[-2:2:-2], range(6, -6, -2))
  
      def test_stepped_slice_rev_range(self):
          r = range(8, -8, -1)
          self.assertRangesEqual(r[::2], range(8, -8, -2))
          self.assertRangesEqual(r[:2:2], range(8, 6, -2))
          self.assertRangesEqual(r[:-2:2], range(8, -6, -2))
          self.assertRangesEqual(r[2::2], range(6, -8, -2))
          self.assertRangesEqual(r[-2::2], range(-6, -8, -2))
          self.assertRangesEqual(r[2:-2:2], range(6, -6, -2))
  
      def test_rev_stepped_slice_rev_range(self):
          r = range(8, -8, -1)
          self.assertRangesEqual(r[::-2], range(-7, 9, 2))
          self.assertRangesEqual(r[:2:-2], range(-7, 6, 2))
          self.assertRangesEqual(r[:-2:-2], range(-7, -6, 2))
          self.assertRangesEqual(r[2::-2], range(6, 9, 2))
          self.assertRangesEqual(r[-2::-2], range(-6, 9, 2))
          self.assertRangesEqual(r[-2:2:-2], range(-6, 6, 2))
  
      def test_slice_stepped_range(self):
          r = range(-8, 8, 2)
          self.assertRangesEqual(r[:], range(-8, 8, 2))
          self.assertRangesEqual(r[:2], range(-8, -4, 2))
          self.assertRangesEqual(r[:-2], range(-8, 4, 2))
          self.assertRangesEqual(r[2:], range(-4, 8, 2))
          self.assertRangesEqual(r[-2:], range(4, 8, 2))
          self.assertRangesEqual(r[2:-2], range(-4, 4, 2))
  
      def test_rev_slice_stepped_range(self):
          r = range(-8, 8, 2)
          self.assertRangesEqual(r[::-1], range(6, -10, -2))
          self.assertRangesEqual(r[:2:-1], range(6, -4, -2))
          self.assertRangesEqual(r[:-2:-1], range(6, 4, -2))
          self.assertRangesEqual(r[2::-1], range(-4, -10, -2))
          self.assertRangesEqual(r[-2::-1], range(4, -10, -2))
          self.assertRangesEqual(r[-2:2:-1], range(4, -4, -2))
  
      def test_slice_rev_stepped_range(self):
          r = range(8, -8, -2)
          self.assertRangesEqual(r[:], range(8, -8, -2))
          self.assertRangesEqual(r[:2], range(8, 4, -2))
          self.assertRangesEqual(r[:-2], range(8, -4, -2))
          self.assertRangesEqual(r[2:], range(4, -8, -2))
          self.assertRangesEqual(r[-2:], range(-4, -8, -2))
          self.assertRangesEqual(r[2:-2], range(4, -4, -2))
  
      def test_rev_slice_rev_stepped_range(self):
          r = range(8, -8, -2)
          self.assertRangesEqual(r[::-1], range(-6, 10, 2))
          self.assertRangesEqual(r[:2:-1], range(-6, 4, 2))
          self.assertRangesEqual(r[:-2:-1], range(-6, -4, 2))
          self.assertRangesEqual(r[2::-1], range(4, 10, 2))
          self.assertRangesEqual(r[-2::-1], range(-4, 10, 2))
          self.assertRangesEqual(r[-2:2:-1], range(-4, 4, 2))
  
      def test_stepped_slice_stepped_range(self):
          r = range(-8, 8, 2)
          self.assertRangesEqual(r[::2], range(-8, 8, 4))
          self.assertRangesEqual(r[:2:2], range(-8, -4, 4))
          self.assertRangesEqual(r[:-2:2], range(-8, 4, 4))
          self.assertRangesEqual(r[2::2], range(-4, 8, 4))
          self.assertRangesEqual(r[-2::2], range(4, 8, 4))
          self.assertRangesEqual(r[2:-2:2], range(-4, 4, 4))
  
      def test_rev_stepped_slice_stepped_range(self):
          r = range(-8, 8, 2)
          self.assertRangesEqual(r[::-2], range(6, -10, -4))
          self.assertRangesEqual(r[:2:-2], range(6, -4, -4))
          self.assertRangesEqual(r[:-2:-2], range(6, 4, -4))
          self.assertRangesEqual(r[2::-2], range(-4, -10, -4))
          self.assertRangesEqual(r[-2::-2], range(4, -10, -4))
          self.assertRangesEqual(r[-2:2:-2], range(4, -4, -4))
  
      def test_stepped_slice_rev_stepped_range(self):
          r = range(8, -8, -2)
          self.assertRangesEqual(r[::2], range(8, -8, -4))
          self.assertRangesEqual(r[:2:2], range(8, 4, -4))
          self.assertRangesEqual(r[:-2:2], range(8, -4, -4))
          self.assertRangesEqual(r[2::2], range(4, -8, -4))
          self.assertRangesEqual(r[-2::2], range(-4, -8, -4))
          self.assertRangesEqual(r[2:-2:2], range(4, -4, -4))
  
      def test_rev_stepped_slice_rev_stepped_range(self):
          r = range(8, -8, -2)
          self.assertRangesEqual(r[::-2], range(-6, 10, 4))
          self.assertRangesEqual(r[:2:-2], range(-6, 4, 4))
          self.assertRangesEqual(r[:-2:-2], range(-6, -4, 4))
          self.assertRangesEqual(r[2::-2], range(4, 10, 4))
          self.assertRangesEqual(r[-2::-2], range(-4, 10, 4))
          self.assertRangesEqual(r[-2:2:-2], range(-4, 4, 4))
  
      def test_slice_zero_step(self):
          msg = '^slice step cannot be zero$'
          with self.assertRaisesRegexp(ValueError, msg):
              range(8)[::0]
  
      def test_properties(self):
          # Exception string differs between PY2/3
          r = range(0)
          with self.assertRaises(AttributeError):
              r.start = 0
          with self.assertRaises(AttributeError):
              r.stop = 0
          with self.assertRaises(AttributeError):
              r.step = 0
  
  
  if __name__ == '__main__':
      unittest.main()
  