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Diffstat (limited to 'lib/python2.7/test/test_xrange.py')
| -rw-r--r-- | lib/python2.7/test/test_xrange.py | 218 |
1 files changed, 218 insertions, 0 deletions
diff --git a/lib/python2.7/test/test_xrange.py b/lib/python2.7/test/test_xrange.py new file mode 100644 index 0000000..83c0e41 --- /dev/null +++ b/lib/python2.7/test/test_xrange.py @@ -0,0 +1,218 @@ +# Python test set -- built-in functions + +import test.test_support, unittest +import sys +import pickle +import itertools + +import warnings +warnings.filterwarnings("ignore", "integer argument expected", + DeprecationWarning, "unittest") + +# pure Python implementations (3 args only), for comparison +def pyrange(start, stop, step): + if (start - stop) // step < 0: + # replace stop with next element in the sequence of integers + # that are congruent to start modulo step. + stop += (start - stop) % step + while start != stop: + yield start + start += step + +def pyrange_reversed(start, stop, step): + stop += (start - stop) % step + return pyrange(stop - step, start - step, -step) + + +class XrangeTest(unittest.TestCase): + def assert_iterators_equal(self, xs, ys, test_id, limit=None): + # check that an iterator xs matches the expected results ys, + # up to a given limit. + if limit is not None: + xs = itertools.islice(xs, limit) + ys = itertools.islice(ys, limit) + sentinel = object() + pairs = itertools.izip_longest(xs, ys, fillvalue=sentinel) + for i, (x, y) in enumerate(pairs): + if x == y: + continue + elif x == sentinel: + self.fail('{}: iterator ended unexpectedly ' + 'at position {}; expected {}'.format(test_id, i, y)) + elif y == sentinel: + self.fail('{}: unexpected excess element {} at ' + 'position {}'.format(test_id, x, i)) + else: + self.fail('{}: wrong element at position {};' + 'expected {}, got {}'.format(test_id, i, y, x)) + + def assert_xranges_equivalent(self, x, y): + # Check that two xrange objects are equivalent, in the sense of the + # associated sequences being the same. We want to use this for large + # xrange objects, so instead of converting to lists and comparing + # directly we do a number of indirect checks. + if len(x) != len(y): + self.fail('{} and {} have different ' + 'lengths: {} and {} '.format(x, y, len(x), len(y))) + if len(x) >= 1: + if x[0] != y[0]: + self.fail('{} and {} have different initial ' + 'elements: {} and {} '.format(x, y, x[0], y[0])) + if x[-1] != y[-1]: + self.fail('{} and {} have different final ' + 'elements: {} and {} '.format(x, y, x[-1], y[-1])) + if len(x) >= 2: + x_step = x[1] - x[0] + y_step = y[1] - y[0] + if x_step != y_step: + self.fail('{} and {} have different step: ' + '{} and {} '.format(x, y, x_step, y_step)) + + def test_xrange(self): + self.assertEqual(list(xrange(3)), [0, 1, 2]) + self.assertEqual(list(xrange(1, 5)), [1, 2, 3, 4]) + self.assertEqual(list(xrange(0)), []) + self.assertEqual(list(xrange(-3)), []) + self.assertEqual(list(xrange(1, 10, 3)), [1, 4, 7]) + self.assertEqual(list(xrange(5, -5, -3)), [5, 2, -1, -4]) + + a = 10 + b = 100 + c = 50 + + self.assertEqual(list(xrange(a, a+2)), [a, a+1]) + self.assertEqual(list(xrange(a+2, a, -1L)), [a+2, a+1]) + self.assertEqual(list(xrange(a+4, a, -2)), [a+4, a+2]) + + seq = list(xrange(a, b, c)) + self.assertIn(a, seq) + self.assertNotIn(b, seq) + self.assertEqual(len(seq), 2) + + seq = list(xrange(b, a, -c)) + self.assertIn(b, seq) + self.assertNotIn(a, seq) + self.assertEqual(len(seq), 2) + + seq = list(xrange(-a, -b, -c)) + self.assertIn(-a, seq) + self.assertNotIn(-b, seq) + self.assertEqual(len(seq), 2) + + self.assertRaises(TypeError, xrange) + self.assertRaises(TypeError, xrange, 1, 2, 3, 4) + self.assertRaises(ValueError, xrange, 1, 2, 0) + + self.assertRaises(OverflowError, xrange, 10**100, 10**101, 10**101) + + self.assertRaises(TypeError, xrange, 0, "spam") + self.assertRaises(TypeError, xrange, 0, 42, "spam") + + self.assertEqual(len(xrange(0, sys.maxint, sys.maxint-1)), 2) + + self.assertRaises(OverflowError, xrange, -sys.maxint, sys.maxint) + self.assertRaises(OverflowError, xrange, 0, 2*sys.maxint) + + r = xrange(-sys.maxint, sys.maxint, 2) + self.assertEqual(len(r), sys.maxint) + self.assertRaises(OverflowError, xrange, -sys.maxint-1, sys.maxint, 2) + + 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 = xrange(*t) + self.assertEqual(list(pickle.loads(pickle.dumps(r, proto))), + list(r)) + + M = min(sys.maxint, sys.maxsize) + large_testcases = testcases + [ + (0, M, 1), + (M, 0, -1), + (0, M, M - 1), + (M // 2, M, 1), + (0, -M, -1), + (0, -M, 1 - M), + (-M, M, 2), + (-M, M, 1024), + (-M, M, 10585), + (M, -M, -2), + (M, -M, -1024), + (M, -M, -10585), + ] + for proto in range(pickle.HIGHEST_PROTOCOL + 1): + for t in large_testcases: + r = xrange(*t) + r_out = pickle.loads(pickle.dumps(r, proto)) + self.assert_xranges_equivalent(r_out, r) + + def test_repr(self): + # Check that repr of an xrange is a valid representation + # of that xrange. + + # Valid xranges have at most min(sys.maxint, sys.maxsize) elements. + M = min(sys.maxint, sys.maxsize) + + testcases = [ + (13,), + (0, 11), + (-22, 10), + (20, 3, -1), + (13, 21, 3), + (-2, 2, 2), + (0, M, 1), + (M, 0, -1), + (0, M, M - 1), + (M // 2, M, 1), + (0, -M, -1), + (0, -M, 1 - M), + (-M, M, 2), + (-M, M, 1024), + (-M, M, 10585), + (M, -M, -2), + (M, -M, -1024), + (M, -M, -10585), + ] + for t in testcases: + r = xrange(*t) + r_out = eval(repr(r)) + self.assert_xranges_equivalent(r, r_out) + + def test_range_iterators(self): + # see issue 7298 + limits = [base + jiggle + for M in (2**32, 2**64) + for base in (-M, -M//2, 0, M//2, M) + for jiggle in (-2, -1, 0, 1, 2)] + test_ranges = [(start, end, step) + for start in limits + for end in limits + for step in (-2**63, -2**31, -2, -1, 1, 2)] + + for start, end, step in test_ranges: + try: + iter1 = xrange(start, end, step) + except OverflowError: + pass + else: + iter2 = pyrange(start, end, step) + test_id = "xrange({}, {}, {})".format(start, end, step) + # check first 100 entries + self.assert_iterators_equal(iter1, iter2, test_id, limit=100) + + try: + iter1 = reversed(xrange(start, end, step)) + except OverflowError: + pass + else: + iter2 = pyrange_reversed(start, end, step) + test_id = "reversed(xrange({}, {}, {}))".format(start, end, step) + self.assert_iterators_equal(iter1, iter2, test_id, limit=100) + + +def test_main(): + test.test_support.run_unittest(XrangeTest) + +if __name__ == "__main__": + test_main() |