Breaking ground for PEP 3137 implementation:

Get rid of buffer().  Use memoryview() in its place where possible.
In a few places, do things a bit different, because memoryview()
can't slice (yet).

Lib/test/test_io.py

@@ -251,7 +251,7 @@ class IOTest(unittest.TestCase):
 
     def test_array_writes(self):
         a = array.array('i', range(10))
-        n = len(buffer(a))
+        n = len(memoryview(a))
         f = io.open(test_support.TESTFN, "wb", 0)
         self.assertEqual(f.write(a), n)
         f.close()