--- old/python/weakref.py
+++ new/python/weakref.py
@@ -206,7 +206,11 @@
             if o is not None:
                 L.append(o)
         return L
-
+        
+    def clear(self):
+        L = self.data.keys();
+        self.data.clear();
+        del L
 
 class KeyedRef(ref):
     """Specialized reference that includes a key corresponding to the value.
@@ -377,3 +381,8 @@
                 d[ref(key, self._remove)] = value
         if len(kwargs):
             self.update(kwargs)
+
+    def clear(self):
+        L = self.data.values();
+        self.data.clear();
+        del L