lib-python.2.7.test.test_xrange.py Maven / Gradle / Ivy
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Jython is an implementation of the high-level, dynamic, object-oriented
language Python written in 100% Pure Java, and seamlessly integrated with
the Java platform. It thus allows you to run Python on any Java platform.
# 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()