Bug #1575169: operator.isSequenceType() now returns False for subclasses of dict.

Lib/test/test_operator.py

@@ -215,6 +215,8 @@ class OperatorTestCase(unittest.TestCase):
         self.failUnless(operator.isSequenceType(xrange(10)))
         self.failUnless(operator.isSequenceType('yeahbuddy'))
         self.failIf(operator.isSequenceType(3))
+        class Dict(dict): pass
+        self.failIf(operator.isSequenceType(Dict()))
 
     def test_lshift(self):
         self.failUnlessRaises(TypeError, operator.lshift)

Misc/NEWS

@@ -103,6 +103,8 @@ Core and builtins
 Extension Modules
 -----------------
 
+- Bug #1575169: operator.isSequenceType() now returns False for subclasses of dict.
+
 - collections.defaultdict() now verifies that the factory function is callable.
 
 - Bug #1486663: don't reject keyword arguments for subclasses of builtin

Objects/abstract.c

@@ -1157,6 +1157,8 @@ PySequence_Check(PyObject *s)
 {
 	if (s && PyInstance_Check(s))
 		return PyObject_HasAttrString(s, "__getitem__");
+	if (PyObject_IsInstance(s, &PyDict_Type))
+		return 0;
 	return s != NULL && s->ob_type->tp_as_sequence &&
 		s->ob_type->tp_as_sequence->sq_item != NULL;
 }