# 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()