No need to assign the results of expressions used only for side effects.
diff --git a/Lib/UserDict.py b/Lib/UserDict.py
index 0497f65..bd64f84 100644
--- a/Lib/UserDict.py
+++ b/Lib/UserDict.py
@@ -98,7 +98,7 @@
             yield k
     def has_key(self, key):
         try:
-            value = self[key]
+            self[key]
         except KeyError:
             return False
         return True