Issue 10889: Support slicing and indexing of large ranges (no docs changes, since, as far as I know, we never said anywhere that this *didn't* work)
diff --git a/Lib/test/test_range.py b/Lib/test/test_range.py
index 5aa5920..fc310c1 100644
--- a/Lib/test/test_range.py
+++ b/Lib/test/test_range.py
@@ -125,23 +125,102 @@
self.assertIn(a, seq)
self.assertNotIn(b, seq)
self.assertEqual(len(seq), 2)
+ self.assertEqual(seq[0], a)
+ self.assertEqual(seq[-1], a+c)
seq = list(range(b, a, -c))
self.assertIn(b, seq)
self.assertNotIn(a, seq)
self.assertEqual(len(seq), 2)
+ self.assertEqual(seq[0], b)
+ self.assertEqual(seq[-1], b-c)
seq = list(range(-a, -b, -c))
self.assertIn(-a, seq)
self.assertNotIn(-b, seq)
self.assertEqual(len(seq), 2)
+ self.assertEqual(seq[0], -a)
+ self.assertEqual(seq[-1], -a-c)
- self.assertRaises(OverflowError, len,
- range(-sys.maxsize, sys.maxsize))
- self.assertRaises(OverflowError, len,
- range(0, 2*sys.maxsize))
- self.assertRaises(OverflowError, len,
- range(0, sys.maxsize**10))
+ def test_large_range(self):
+ # Check long ranges (len > sys.maxsize)
+ # len() is expected to fail due to limitations of the __len__ protocol
+ def _range_len(x):
+ try:
+ length = len(x)
+ except OverflowError:
+ step = x[1] - x[0]
+ length = 1 + ((x[-1] - x[0]) // step)
+ return length
+ a = -sys.maxsize
+ b = sys.maxsize
+ expected_len = b - a
+ x = range(a, b)
+ self.assertIn(a, x)
+ self.assertNotIn(b, x)
+ self.assertRaises(OverflowError, len, x)
+ self.assertEqual(_range_len(x), expected_len)
+ self.assertEqual(x[0], a)
+ idx = sys.maxsize+1
+ self.assertEqual(x[idx], a+idx)
+ self.assertEqual(x[idx:idx+1][0], a+idx)
+ with self.assertRaises(IndexError):
+ x[-expected_len-1]
+ with self.assertRaises(IndexError):
+ x[expected_len]
+
+ a = 0
+ b = 2 * sys.maxsize
+ expected_len = b - a
+ x = range(a, b)
+ self.assertIn(a, x)
+ self.assertNotIn(b, x)
+ self.assertRaises(OverflowError, len, x)
+ self.assertEqual(_range_len(x), expected_len)
+ self.assertEqual(x[0], a)
+ idx = sys.maxsize+1
+ self.assertEqual(x[idx], a+idx)
+ self.assertEqual(x[idx:idx+1][0], a+idx)
+ with self.assertRaises(IndexError):
+ x[-expected_len-1]
+ with self.assertRaises(IndexError):
+ x[expected_len]
+
+ a = 0
+ b = sys.maxsize**10
+ c = 2*sys.maxsize
+ expected_len = 1 + (b - a) // c
+ x = range(a, b, c)
+ self.assertIn(a, x)
+ self.assertNotIn(b, x)
+ self.assertRaises(OverflowError, len, x)
+ self.assertEqual(_range_len(x), expected_len)
+ self.assertEqual(x[0], a)
+ idx = sys.maxsize+1
+ self.assertEqual(x[idx], a+(idx*c))
+ self.assertEqual(x[idx:idx+1][0], a+(idx*c))
+ with self.assertRaises(IndexError):
+ x[-expected_len-1]
+ with self.assertRaises(IndexError):
+ x[expected_len]
+
+ a = sys.maxsize**10
+ b = 0
+ c = -2*sys.maxsize
+ expected_len = 1 + (b - a) // c
+ x = range(a, b, c)
+ self.assertIn(a, x)
+ self.assertNotIn(b, x)
+ self.assertRaises(OverflowError, len, x)
+ self.assertEqual(_range_len(x), expected_len)
+ self.assertEqual(x[0], a)
+ idx = sys.maxsize+1
+ self.assertEqual(x[idx], a+(idx*c))
+ self.assertEqual(x[idx:idx+1][0], a+(idx*c))
+ with self.assertRaises(IndexError):
+ x[-expected_len-1]
+ with self.assertRaises(IndexError):
+ x[expected_len]
def test_invalid_invocation(self):
self.assertRaises(TypeError, range)