Index: Objects/dictobject.c
===================================================================
--- Objects/dictobject.c	(revision 83091)
+++ Objects/dictobject.c	(working copy)
@@ -2807,7 +2807,55 @@
     (binaryfunc)dictviews_or,           /*nb_or*/
 };
 
+/* isdisjoint for dict_keys and dict_items */
+static PyObject*
+dictviews_isdisjoint(PyObject *self, PyObject *other)
+{
+    PyObject *it;
+    PyObject *item=NULL;
+    int contains;
+
+    assert(self != NULL);
+    assert(PyDictViewSet_Check(self));
+    assert(other != NULL);
+
+    if (self == other) {
+        if (dictview_len((dictviewobject *)self) == 0) {
+            Py_RETURN_TRUE;
+        }
+        else {
+            Py_RETURN_FALSE;
+        }
+    }
+
+    it = PyObject_GetIter(other);
+    if (it == NULL) {
+        return NULL;
+    }
+
+    while ((item = PyIter_Next(it)) != NULL) {
+        contains = PySequence_Contains(self, item);
+        Py_DECREF(item);
+        if (contains == -1) {
+            Py_DECREF(it);
+            return NULL;
+        }
+
+        if (contains) {
+            Py_DECREF(it);
+            Py_RETURN_FALSE;
+        }
+    }
+    Py_DECREF(it);
+    Py_RETURN_TRUE;
+}
+
+PyDoc_STRVAR(isdisjoint_doc,
+"Return True if the view and the given iterable have a null intersection.");
+
 static PyMethodDef dictkeys_methods[] = {
+    {"isdisjoint",      (PyCFunction)dictviews_isdisjoint,  METH_O,
+     isdisjoint_doc},
     {NULL,              NULL}           /* sentinel */
 };
 
@@ -2892,6 +2940,8 @@
 };
 
 static PyMethodDef dictitems_methods[] = {
+    {"isdisjoint",      (PyCFunction)dictviews_isdisjoint,  METH_O,
+     isdisjoint_doc},
     {NULL,              NULL}           /* sentinel */
 };
 
Index: Lib/test/test_dictviews.py
===================================================================
--- Lib/test/test_dictviews.py	(revision 83091)
+++ Lib/test/test_dictviews.py	(working copy)
@@ -112,6 +112,16 @@
         self.assertEqual(d1.keys() ^ set(d3.keys()),
                          {'a', 'b', 'd', 'e'})
 
+        # issue 9212: test dict_keys.isdisjoint:
+        self.assertFalse(d1.keys().isdisjoint(d1.keys()))
+        self.assertFalse(d1.keys().isdisjoint(d2.keys()))
+        self.assertTrue(d1.keys().isdisjoint({'x', 'y'}))
+        self.assertTrue(d1.keys().isdisjoint(d3.keys()))
+
+        de = {}
+        self.assertTrue(de.keys().isdisjoint(set()))
+        self.assertTrue(de.keys().isdisjoint(de.keys()))
+
     def test_items_set_operations(self):
         d1 = {'a': 1, 'b': 2}
         d2 = {'a': 2, 'b': 2}
@@ -144,7 +154,17 @@
         self.assertEqual(d1.items() ^ d3.items(),
                          {('a', 1), ('b', 2), ('d', 4), ('e', 5)})
 
+        # issue 9212: test dict_items.isdisjoint:
+        self.assertFalse(d1.items().isdisjoint(d1.items()))
+        self.assertFalse(d1.items().isdisjoint(d2.items()))
+        self.assertTrue(d1.items().isdisjoint({'x', 'y'}))
+        self.assertTrue(d1.items().isdisjoint(d3.items()))
 
+        de = {}
+        self.assertTrue(de.items().isdisjoint(set()))
+        self.assertTrue(de.items().isdisjoint(de.items()))
+
+
 def test_main():
     support.run_unittest(DictSetTest)