Fix compatibility for earlier versions of Python (than 2.3), which
doesn't have UserDict.DictMixin.
diff --git a/Lib/bsddb/dbobj.py b/Lib/bsddb/dbobj.py
index f274d56..889e554 100644
--- a/Lib/bsddb/dbobj.py
+++ b/Lib/bsddb/dbobj.py
@@ -16,7 +16,12 @@
 #
 
 import db
-from UserDict import DictMixin
+
+try:
+    from UserDict import DictMixin
+except ImportError:
+    # DictMixin is new in Python 2.3
+    class DictMixin: pass
 
 class DBEnv:
     def __init__(self, *args, **kwargs):