Issue #24286: Register dict views with the MappingView ABCs.

rhettinger · rhettinger · commit c4282a0f2340 · 2015-05-26T01:35:54.000-07:00
diff --git a/Lib/_abcoll.py b/Lib/_abcoll.py
@@ -453,6 +453,7 @@ def __iter__(self):
         for key in self._mapping:
             yield key
 
+KeysView.register(type({}.viewkeys()))
 
 class ItemsView(MappingView, Set):
 
@@ -473,6 +474,7 @@ def __iter__(self):
         for key in self._mapping:
             yield (key, self._mapping[key])
 
+ItemsView.register(type({}.viewitems()))
 
 class ValuesView(MappingView):
 
@@ -486,6 +488,7 @@ def __iter__(self):
         for key in self._mapping:
             yield self._mapping[key]
 
+ValuesView.register(type({}.viewvalues()))
 
 class MutableMapping(Mapping):
 
diff --git a/Lib/test/test_collections.py b/Lib/test/test_collections.py
@@ -1286,6 +1286,10 @@ def test_views(self):
         self.assertEqual(list(od.viewvalues()),  [None for k in s])
         self.assertEqual(list(od.viewitems()),  [(k, None) for k in s])
 
+        # See http://bugs.python.org/issue24286
+        self.assertEqual(od.viewkeys(), dict(od).viewkeys())
+        self.assertEqual(od.viewitems(), dict(od).viewitems())
+
     def test_override_update(self):
         # Verify that subclasses can override update() without breaking __init__()
         class MyOD(OrderedDict):
diff --git a/Lib/test/test_dictviews.py b/Lib/test/test_dictviews.py
@@ -1,4 +1,5 @@
 import unittest
+import collections
 from test import test_support
 
 class DictSetTest(unittest.TestCase):
@@ -164,7 +165,26 @@ def test_recursive_repr(self):
         d[42] = d.viewvalues()
         self.assertRaises(RuntimeError, repr, d)
 
-
+    def test_abc_registry(self):
+        d = dict(a=1)
+
+        self.assertIsInstance(d.viewkeys(), collections.KeysView)
+        self.assertIsInstance(d.viewkeys(), collections.MappingView)
+        self.assertIsInstance(d.viewkeys(), collections.Set)
+        self.assertIsInstance(d.viewkeys(), collections.Sized)
+        self.assertIsInstance(d.viewkeys(), collections.Iterable)
+        self.assertIsInstance(d.viewkeys(), collections.Container)
+
+        self.assertIsInstance(d.viewvalues(), collections.ValuesView)
+        self.assertIsInstance(d.viewvalues(), collections.MappingView)
+        self.assertIsInstance(d.viewvalues(), collections.Sized)
+
+        self.assertIsInstance(d.viewitems(), collections.ItemsView)
+        self.assertIsInstance(d.viewitems(), collections.MappingView)
+        self.assertIsInstance(d.viewitems(), collections.Set)
+        self.assertIsInstance(d.viewitems(), collections.Sized)
+        self.assertIsInstance(d.viewitems(), collections.Iterable)
+        self.assertIsInstance(d.viewitems(), collections.Container)
 
 
 def test_main():
diff --git a/Misc/NEWS b/Misc/NEWS
@@ -21,6 +21,10 @@ Library
 - Issue #24257: Fixed segmentation fault in sqlite3.Row constructor with faked
   cursor type.
 
+- Issue #24286:  Dict view were not registered with the MappingView abstract
+  base classes.  This caused key and item views in OrderedDict to not be equal
+  to their regular dict counterparts.
+
 - Issue #22107: tempfile.gettempdir() and tempfile.mkdtemp() now try again
   when a directory with the chosen name already exists on Windows as well as
   on Unix.  tempfile.mkstemp() now fails early if parent directory is not
