--- a/web/facet.py	Mon Mar 11 18:37:01 2013 +0100
+++ b/web/facet.py	Fri Feb 22 19:36:40 2013 +0100
@@ -49,6 +49,7 @@
 __docformat__ = "restructuredtext en"
 _ = unicode
 
+from functools import reduce
 from warnings import warn
 from copy import deepcopy
 from datetime import datetime, timedelta