diff -r e55cc0834e9c Lib/test/list_tests.py
--- a/Lib/test/list_tests.py	Wed Apr 15 17:08:45 2015 -0400
+++ b/Lib/test/list_tests.py	Wed Apr 15 18:15:35 2015 -0400
@@ -102,13 +102,27 @@
         self.assertEqual(a, self.type2test([0, 200]))
         a[-2] = 100
         self.assertEqual(a, self.type2test([100, 200]))
-        self.assertRaises(IndexError, a.__setitem__, -3, 200)
-        self.assertRaises(IndexError, a.__setitem__, 2, 200)
+
+        with self.assertRaises(IndexError) as context:
+            a.__setitem__(-3, 200)
+        self.assertEqual(context.exception.index, -3)
+        self.assertEqual(context.exception.length, 2)
+
+        with self.assertRaises(IndexError) as context:
+            a.__setitem__(2, 200)
+        self.assertEqual(context.exception.index, 2)
+        self.assertEqual(context.exception.length, 2)
 
         a = self.type2test([])
-        self.assertRaises(IndexError, a.__setitem__, 0, 200)
-        self.assertRaises(IndexError, a.__setitem__, -1, 200)
         self.assertRaises(TypeError, a.__setitem__)
+        with self.assertRaises(IndexError) as context:
+            a.__setitem__(0, 200)
+        self.assertEqual(context.exception.index, 0)
+        self.assertEqual(context.exception.length, 0)
+        with self.assertRaises(IndexError) as context:
+            a.__setitem__(-1, 200)
+        self.assertEqual(context.exception.index, -1)
+        self.assertEqual(context.exception.length, 0)
 
         a = self.type2test([0,1,2,3,4])
         a[0] = 1
diff -r e55cc0834e9c Lib/test/seq_tests.py
--- a/Lib/test/seq_tests.py	Wed Apr 15 17:08:45 2015 -0400
+++ b/Lib/test/seq_tests.py	Wed Apr 15 18:15:35 2015 -0400
@@ -319,8 +319,14 @@
         self.assertEqual(a.__getitem__(1), 11)
         self.assertEqual(a.__getitem__(-2), 10)
         self.assertEqual(a.__getitem__(-1), 11)
-        self.assertRaises(IndexError, a.__getitem__, -3)
-        self.assertRaises(IndexError, a.__getitem__, 3)
+        with self.assertRaises(IndexError) as context:
+            a.__getitem__(3)
+        self.assertEqual(context.exception.index, 3)
+        self.assertEqual(context.exception.length, 2)
+        with self.assertRaises(IndexError) as context:
+            a.__getitem__(-3)
+        self.assertEqual(context.exception.index, -3)
+        self.assertEqual(context.exception.length, 2)
         self.assertEqual(a.__getitem__(slice(0,1)), self.type2test([10]))
         self.assertEqual(a.__getitem__(slice(1,2)), self.type2test([11]))
         self.assertEqual(a.__getitem__(slice(0,2)), self.type2test([10, 11]))
diff -r e55cc0834e9c Lib/test/test_exceptions.py
--- a/Lib/test/test_exceptions.py	Wed Apr 15 17:08:45 2015 -0400
+++ b/Lib/test/test_exceptions.py	Wed Apr 15 18:15:35 2015 -0400
@@ -377,6 +377,23 @@
                                              'pickled "%r", attribute "%s' %
                                              (e, checkArgName))
 
+    def testIndexErrorAttributes(self):
+        exc = IndexError('spam')
+        self.assertIsNone(exc.index)
+        self.assertIsNone(exc.length)
+
+        exc = IndexError('spam', index=1)
+        self.assertEqual(exc.index, 1)
+        self.assertIsNone(exc.length)
+
+        exc = IndexError('spam', length=2)
+        self.assertIsNone(exc.index)
+        self.assertEqual(exc.length, 2)
+
+        exc = IndexError('spam', index=2, length=1)
+        self.assertEqual(exc.index, 2)
+        self.assertEqual(exc.length, 1)
+
     def testWithTraceback(self):
         try:
             raise IndexError(4)