Issue 6329: Fix iteration for memoryviews.

Lib/test/test_memoryview.py

@@ -48,6 +48,12 @@ class AbstractMemoryTests:
         for tp in self._types:
             self.check_getitem_with_type(tp)
 
+    def test_iter(self):
+        for tp in self._types:
+            b = tp(self._source)
+            m = self._view(b)
+            self.assertEqual(list(m), [m[i] for i in range(len(m))])
+
     def test_setitem_readonly(self):
         if not self.ro_type:
             return

Misc/NEWS

@@ -12,6 +12,9 @@ What's New in Python 3.1?
 Core and Builtins
 -----------------
 
+- Issue #6329: Fixed iteration for memoryview objects (it was being blocked
+  because it wasn't recognized as a sequence).
+
 Library
 -------
 

Objects/memoryobject.c

@@ -505,37 +505,19 @@ memory_length(PyMemoryViewObject *self)
     return get_shape0(&self->view);
 }
 
-/*
-  mem[obj] returns a bytes object holding the data for one element if
-           obj fully indexes the memory view or another memory-view object
-           if it does not.
-
-           0-d memory-view objects can be referenced using ... or () but
-           not with anything else.
- */
+/* Alternate version of memory_subcript that only accepts indices.
+   Used by PySeqIter_New().
+*/
 static PyObject *
-memory_subscript(PyMemoryViewObject *self, PyObject *key)
+memory_item(PyMemoryViewObject *self, Py_ssize_t result)
 {
-    Py_buffer *view;
-    view = &(self->view);
+    Py_buffer *view = &(self->view);
 
     if (view->ndim == 0) {
-        if (key == Py_Ellipsis ||
-            (PyTuple_Check(key) && PyTuple_GET_SIZE(key)==0)) {
-            Py_INCREF(self);
-            return (PyObject *)self;
-        }
-        else {
         PyErr_SetString(PyExc_IndexError,
                         "invalid indexing of 0-dim memory");
         return NULL;
     }
-    }
-    if (PyIndex_Check(key)) {
-        Py_ssize_t result;
-        result = PyNumber_AsSsize_t(key, NULL);
-        if (result == -1 && PyErr_Occurred())
-                return NULL;
     if (view->ndim == 1) {
         /* Return a bytes object */
         char *ptr;
@@ -557,16 +539,47 @@ memory_subscript(PyMemoryViewObject *self, PyObject *key)
             ptr = *((char **)ptr) + view->suboffsets[0];
         }
         return PyBytes_FromStringAndSize(ptr, view->itemsize);
-        }
-        else {
+    } else {
         /* Return a new memory-view object */
         Py_buffer newview;
         memset(&newview, 0, sizeof(newview));
-            /* XXX:  This needs to be fixed so it
-                         actually returns a sub-view
-            */
+        /* XXX:  This needs to be fixed so it actually returns a sub-view */
         return PyMemoryView_FromBuffer(&newview);
     }
+}
+
+/*
+  mem[obj] returns a bytes object holding the data for one element if
+           obj fully indexes the memory view or another memory-view object
+           if it does not.
+
+           0-d memory-view objects can be referenced using ... or () but
+           not with anything else.
+ */
+static PyObject *
+memory_subscript(PyMemoryViewObject *self, PyObject *key)
+{
+    Py_buffer *view;
+    view = &(self->view);
+    
+    if (view->ndim == 0) {
+        if (key == Py_Ellipsis ||
+            (PyTuple_Check(key) && PyTuple_GET_SIZE(key)==0)) {
+            Py_INCREF(self);
+            return (PyObject *)self;
+        }
+        else {
+            PyErr_SetString(PyExc_IndexError,
+                                "invalid indexing of 0-dim memory");
+            return NULL;
+        }
+    }
+    if (PyIndex_Check(key)) {
+        Py_ssize_t result;
+        result = PyNumber_AsSsize_t(key, NULL);
+        if (result == -1 && PyErr_Occurred())
+                return NULL;
+        return memory_item(self, result);
     }
     else if (PySlice_Check(key)) {
         Py_ssize_t start, stop, step, slicelength;
@@ -771,6 +784,12 @@ static PyMappingMethods memory_as_mapping = {
     (objobjargproc)memory_ass_sub,        /* mp_ass_subscript */
 };
 
+static PySequenceMethods memory_as_sequence = {
+	0,                                  /* sq_length */
+	0,                                  /* sq_concat */
+	0,                                  /* sq_repeat */
+	(ssizeargfunc)memory_item,          /* sq_item */
+};
 
 /* Buffer methods */
 
@@ -792,7 +811,7 @@ PyTypeObject PyMemoryView_Type = {
     0,                                        /* tp_reserved */
     (reprfunc)memory_repr,                    /* tp_repr */
     0,                                        /* tp_as_number */
-    0,                                        /* tp_as_sequence */
+    &memory_as_sequence,                      /* tp_as_sequence */
     &memory_as_mapping,                       /* tp_as_mapping */
     0,                                        /* tp_hash */
     0,                                        /* tp_call */