key parameter is more efficient and clear than cmp

git-svn-id: https://svn.erp5.org/repos/public/erp5/trunk@32718 20353a03-c40f-0410-a6d1-a30d3c3de9de

product/ERP5Type/XMLMatrix.py

@@ -479,7 +479,7 @@ class XMLMatrix(Folder):
       result = []
       for value in cell_range.itervalues():
         result_items = value.items()
-        result_items.sort(lambda x, y: x[1]-y[1])
+        result_items.sort(key=lamba x:x[1])
         result_items = [x[0] for x in result_items]
         result += [result_items]
       return result