cpython/Lib/test/test_range.py
2010-01-23 15:40:09 +00:00

199 lines
6.9 KiB
Python

# Python test set -- built-in functions
import test.support, unittest
import sys
import pickle
import itertools
# 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 RangeTest(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.zip_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 test_range(self):
self.assertEqual(list(range(3)), [0, 1, 2])
self.assertEqual(list(range(1, 5)), [1, 2, 3, 4])
self.assertEqual(list(range(0)), [])
self.assertEqual(list(range(-3)), [])
self.assertEqual(list(range(1, 10, 3)), [1, 4, 7])
self.assertEqual(list(range(5, -5, -3)), [5, 2, -1, -4])
a = 10
b = 100
c = 50
self.assertEqual(list(range(a, a+2)), [a, a+1])
self.assertEqual(list(range(a+2, a, -1)), [a+2, a+1])
self.assertEqual(list(range(a+4, a, -2)), [a+4, a+2])
seq = list(range(a, b, c))
self.assertIn(a, seq)
self.assertNotIn(b, seq)
self.assertEqual(len(seq), 2)
seq = list(range(b, a, -c))
self.assertIn(b, seq)
self.assertNotIn(a, seq)
self.assertEqual(len(seq), 2)
seq = list(range(-a, -b, -c))
self.assertIn(-a, seq)
self.assertNotIn(-b, seq)
self.assertEqual(len(seq), 2)
self.assertRaises(TypeError, range)
self.assertRaises(TypeError, range, 1, 2, 3, 4)
self.assertRaises(ValueError, range, 1, 2, 0)
self.assertRaises(TypeError, range, 0.0, 2, 1)
self.assertRaises(TypeError, range, 1, 2.0, 1)
self.assertRaises(TypeError, range, 1, 2, 1.0)
self.assertRaises(TypeError, range, 1e100, 1e101, 1e101)
self.assertRaises(TypeError, range, 0, "spam")
self.assertRaises(TypeError, range, 0, 42, "spam")
self.assertEqual(len(range(0, sys.maxsize, sys.maxsize-1)), 2)
r = range(-sys.maxsize, sys.maxsize, 2)
self.assertEqual(len(r), sys.maxsize)
def test_repr(self):
self.assertEqual(repr(range(1)), 'range(0, 1)')
self.assertEqual(repr(range(1, 2)), 'range(1, 2)')
self.assertEqual(repr(range(1, 2, 3)), 'range(1, 2, 3)')
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 = range(*t)
self.assertEquals(list(pickle.loads(pickle.dumps(r, proto))),
list(r))
def test_odd_bug(self):
# This used to raise a "SystemError: NULL result without error"
# because the range validation step was eating the exception
# before NULL was returned.
with self.assertRaises(TypeError):
range([], 1, -1)
def test_types(self):
# Non-integer objects *equal* to any of the range's items are supposed
# to be contained in the range.
self.assertIn(1.0, range(3))
self.assertIn(True, range(3))
self.assertIn(1+0j, range(3))
class C1:
def __eq__(self, other): return True
self.assertIn(C1(), range(3))
# Objects are never coerced into other types for comparison.
class C2:
def __int__(self): return 1
def __index__(self): return 1
self.assertNotIn(C2(), range(3))
# ..except if explicitly told so.
self.assertIn(int(C2()), range(3))
# Check that the range.__contains__ optimization is only
# used for ints, not for instances of subclasses of int.
class C3(int):
def __eq__(self, other): return True
self.assertIn(C3(11), range(10))
self.assertIn(C3(11), list(range(10)))
def test_strided_limits(self):
r = range(0, 101, 2)
self.assertIn(0, r)
self.assertNotIn(1, r)
self.assertIn(2, r)
self.assertNotIn(99, r)
self.assertIn(100, r)
self.assertNotIn(101, r)
r = range(0, -20, -1)
self.assertIn(0, r)
self.assertIn(-1, r)
self.assertIn(-19, r)
self.assertNotIn(-20, r)
r = range(0, -20, -2)
self.assertIn(-18, r)
self.assertNotIn(-19, r)
self.assertNotIn(-20, r)
def test_empty(self):
r = range(0)
self.assertNotIn(0, r)
self.assertNotIn(1, r)
r = range(0, -10)
self.assertNotIn(0, r)
self.assertNotIn(-1, r)
self.assertNotIn(1, r)
def test_range_iterators(self):
# exercise 'fast' iterators, that use a rangeiterobject internally.
# 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:
iter1 = range(start, end, step)
iter2 = pyrange(start, end, step)
test_id = "range({}, {}, {})".format(start, end, step)
# check first 100 entries
self.assert_iterators_equal(iter1, iter2, test_id, limit=100)
iter1 = reversed(range(start, end, step))
iter2 = pyrange_reversed(start, end, step)
test_id = "reversed(range({}, {}, {}))".format(start, end, step)
self.assert_iterators_equal(iter1, iter2, test_id, limit=100)
def test_main():
test.support.run_unittest(RangeTest)
if __name__ == "__main__":
test_main()