1 # Python test set -- built-in functions 2 3 import test.test_support, unittest 4 import sys 5 import pickle 6 import itertools 7 8 import warnings 9 warnings.filterwarnings("ignore", "integer argument expected", 10 DeprecationWarning, "unittest") 11 12 # pure Python implementations (3 args only), for comparison 13 def pyrange(start, stop, step): 14 if (start - stop) // step < 0: 15 # replace stop with next element in the sequence of integers 16 # that are congruent to start modulo step. 17 stop += (start - stop) % step 18 while start != stop: 19 yield start 20 start += step 21 22 def pyrange_reversed(start, stop, step): 23 stop += (start - stop) % step 24 return pyrange(stop - step, start - step, -step) 25 26 27 class XrangeTest(unittest.TestCase): 28 def assert_iterators_equal(self, xs, ys, test_id, limit=None): 29 # check that an iterator xs matches the expected results ys, 30 # up to a given limit. 31 if limit is not None: 32 xs = itertools.islice(xs, limit) 33 ys = itertools.islice(ys, limit) 34 sentinel = object() 35 pairs = itertools.izip_longest(xs, ys, fillvalue=sentinel) 36 for i, (x, y) in enumerate(pairs): 37 if x == y: 38 continue 39 elif x == sentinel: 40 self.fail('{}: iterator ended unexpectedly ' 41 'at position {}; expected {}'.format(test_id, i, y)) 42 elif y == sentinel: 43 self.fail('{}: unexpected excess element {} at ' 44 'position {}'.format(test_id, x, i)) 45 else: 46 self.fail('{}: wrong element at position {};' 47 'expected {}, got {}'.format(test_id, i, y, x)) 48 49 def assert_xranges_equivalent(self, x, y): 50 # Check that two xrange objects are equivalent, in the sense of the 51 # associated sequences being the same. We want to use this for large 52 # xrange objects, so instead of converting to lists and comparing 53 # directly we do a number of indirect checks. 54 if len(x) != len(y): 55 self.fail('{} and {} have different ' 56 'lengths: {} and {} '.format(x, y, len(x), len(y))) 57 if len(x) >= 1: 58 if x[0] != y[0]: 59 self.fail('{} and {} have different initial ' 60 'elements: {} and {} '.format(x, y, x[0], y[0])) 61 if x[-1] != y[-1]: 62 self.fail('{} and {} have different final ' 63 'elements: {} and {} '.format(x, y, x[-1], y[-1])) 64 if len(x) >= 2: 65 x_step = x[1] - x[0] 66 y_step = y[1] - y[0] 67 if x_step != y_step: 68 self.fail('{} and {} have different step: ' 69 '{} and {} '.format(x, y, x_step, y_step)) 70 71 def test_xrange(self): 72 self.assertEqual(list(xrange(3)), [0, 1, 2]) 73 self.assertEqual(list(xrange(1, 5)), [1, 2, 3, 4]) 74 self.assertEqual(list(xrange(0)), []) 75 self.assertEqual(list(xrange(-3)), []) 76 self.assertEqual(list(xrange(1, 10, 3)), [1, 4, 7]) 77 self.assertEqual(list(xrange(5, -5, -3)), [5, 2, -1, -4]) 78 79 a = 10 80 b = 100 81 c = 50 82 83 self.assertEqual(list(xrange(a, a+2)), [a, a+1]) 84 self.assertEqual(list(xrange(a+2, a, -1L)), [a+2, a+1]) 85 self.assertEqual(list(xrange(a+4, a, -2)), [a+4, a+2]) 86 87 seq = list(xrange(a, b, c)) 88 self.assertIn(a, seq) 89 self.assertNotIn(b, seq) 90 self.assertEqual(len(seq), 2) 91 92 seq = list(xrange(b, a, -c)) 93 self.assertIn(b, seq) 94 self.assertNotIn(a, seq) 95 self.assertEqual(len(seq), 2) 96 97 seq = list(xrange(-a, -b, -c)) 98 self.assertIn(-a, seq) 99 self.assertNotIn(-b, seq) 100 self.assertEqual(len(seq), 2) 101 102 self.assertRaises(TypeError, xrange) 103 self.assertRaises(TypeError, xrange, 1, 2, 3, 4) 104 self.assertRaises(ValueError, xrange, 1, 2, 0) 105 106 self.assertRaises(OverflowError, xrange, 10**100, 10**101, 10**101) 107 108 self.assertRaises(TypeError, xrange, 0, "spam") 109 self.assertRaises(TypeError, xrange, 0, 42, "spam") 110 111 self.assertEqual(len(xrange(0, sys.maxint, sys.maxint-1)), 2) 112 113 self.assertRaises(OverflowError, xrange, -sys.maxint, sys.maxint) 114 self.assertRaises(OverflowError, xrange, 0, 2*sys.maxint) 115 116 r = xrange(-sys.maxint, sys.maxint, 2) 117 self.assertEqual(len(r), sys.maxint) 118 self.assertRaises(OverflowError, xrange, -sys.maxint-1, sys.maxint, 2) 119 120 def test_pickling(self): 121 testcases = [(13,), (0, 11), (-22, 10), (20, 3, -1), 122 (13, 21, 3), (-2, 2, 2)] 123 for proto in range(pickle.HIGHEST_PROTOCOL + 1): 124 for t in testcases: 125 r = xrange(*t) 126 self.assertEqual(list(pickle.loads(pickle.dumps(r, proto))), 127 list(r)) 128 129 M = min(sys.maxint, sys.maxsize) 130 large_testcases = testcases + [ 131 (0, M, 1), 132 (M, 0, -1), 133 (0, M, M - 1), 134 (M // 2, M, 1), 135 (0, -M, -1), 136 (0, -M, 1 - M), 137 (-M, M, 2), 138 (-M, M, 1024), 139 (-M, M, 10585), 140 (M, -M, -2), 141 (M, -M, -1024), 142 (M, -M, -10585), 143 ] 144 for proto in range(pickle.HIGHEST_PROTOCOL + 1): 145 for t in large_testcases: 146 r = xrange(*t) 147 r_out = pickle.loads(pickle.dumps(r, proto)) 148 self.assert_xranges_equivalent(r_out, r) 149 150 def test_repr(self): 151 # Check that repr of an xrange is a valid representation 152 # of that xrange. 153 154 # Valid xranges have at most min(sys.maxint, sys.maxsize) elements. 155 M = min(sys.maxint, sys.maxsize) 156 157 testcases = [ 158 (13,), 159 (0, 11), 160 (-22, 10), 161 (20, 3, -1), 162 (13, 21, 3), 163 (-2, 2, 2), 164 (0, M, 1), 165 (M, 0, -1), 166 (0, M, M - 1), 167 (M // 2, M, 1), 168 (0, -M, -1), 169 (0, -M, 1 - M), 170 (-M, M, 2), 171 (-M, M, 1024), 172 (-M, M, 10585), 173 (M, -M, -2), 174 (M, -M, -1024), 175 (M, -M, -10585), 176 ] 177 for t in testcases: 178 r = xrange(*t) 179 r_out = eval(repr(r)) 180 self.assert_xranges_equivalent(r, r_out) 181 182 def test_range_iterators(self): 183 # see issue 7298 184 limits = [base + jiggle 185 for M in (2**32, 2**64) 186 for base in (-M, -M//2, 0, M//2, M) 187 for jiggle in (-2, -1, 0, 1, 2)] 188 test_ranges = [(start, end, step) 189 for start in limits 190 for end in limits 191 for step in (-2**63, -2**31, -2, -1, 1, 2)] 192 193 for start, end, step in test_ranges: 194 try: 195 iter1 = xrange(start, end, step) 196 except OverflowError: 197 pass 198 else: 199 iter2 = pyrange(start, end, step) 200 test_id = "xrange({}, {}, {})".format(start, end, step) 201 # check first 100 entries 202 self.assert_iterators_equal(iter1, iter2, test_id, limit=100) 203 204 try: 205 iter1 = reversed(xrange(start, end, step)) 206 except OverflowError: 207 pass 208 else: 209 iter2 = pyrange_reversed(start, end, step) 210 test_id = "reversed(xrange({}, {}, {}))".format(start, end, step) 211 self.assert_iterators_equal(iter1, iter2, test_id, limit=100) 212 213 214 def test_main(): 215 test.test_support.run_unittest(XrangeTest) 216 217 if __name__ == "__main__": 218 test_main() 219
