Exercise xrange a bit

Lib/test/test_xrange.py

+# Python test set -- built-in functions
+
+import test.test_support, unittest
+import sys
+
+import warnings
+warnings.filterwarnings("ignore", "integer argument expected",
+                        DeprecationWarning, "unittest")
+
+class XrangeTest(unittest.TestCase):
+    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.assert_(a in seq)
+        self.assert_(b not in seq)
+        self.assertEqual(len(seq), 2)
+
+        seq = list(xrange(b, a, -c))
+        self.assert_(b in seq)
+        self.assert_(a not in seq)
+        self.assertEqual(len(seq), 2)
+
+        seq = list(xrange(-a, -b, -c))
+        self.assert_(-a in seq)
+        self.assert_(-b not in 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, 1e100, 1e101, 1e101)
+
+        self.assertRaises(TypeError, xrange, 0, "spam")
+        self.assertRaises(TypeError, xrange, 0, 42, "spam")
+
+        self.assertRaises(OverflowError, xrange, 0, sys.maxint, sys.maxint-1)
+        self.assertRaises(OverflowError, xrange, -sys.maxint, sys.maxint)
+        self.assertRaises(OverflowError, xrange, 0, 2*sys.maxint)
+
+def test_main():
+    test.test_support.run_unittest(XrangeTest)
+
+if __name__ == "__main__":
+    test_main()