Close #19078: memoryview now supports reversed

Patch by Claudiu Popa

Lib/test/test_memoryview.py

@@ -352,6 +352,15 @@ class AbstractMemoryTests:
             self.assertIs(wr(), None)
             self.assertIs(L[0], b)
 
+    def test_reversed(self):
+        for tp in self._types:
+            b = tp(self._source)
+            m = self._view(b)
+            aslist = list(reversed(m.tolist()))
+            self.assertEqual(list(reversed(m)), aslist)
+            self.assertEqual(list(reversed(m)), list(m[::-1]))
+
+
 # Variations on source objects for the buffer: bytes-like objects, then arrays
 # with itemsize > 1.
 # NOTE: support for multi-dimensional objects is unimplemented.

Misc/NEWS

@@ -10,6 +10,10 @@ Projected release date: 2013-10-20
 Core and Builtins
 -----------------
 
+- Issue #19078: memoryview now correctly supports the reversed builtin
+  (Patch by Claudiu Popa)
+
+
 Library
 -------
 

Objects/memoryobject.c

@@ -2402,7 +2402,7 @@ static PyMappingMethods memory_as_mapping = {
 
 /* As sequence */
 static PySequenceMethods memory_as_sequence = {
-        0,                                /* sq_length */
+        (lenfunc)memory_length,           /* sq_length */
         0,                                /* sq_concat */
         0,                                /* sq_repeat */
         (ssizeargfunc)memory_item,        /* sq_item */