Simplify with built-in functions where possible. e.g.

change [x for x in y if x] to filter(None, y)
change [f(x) for x in y] to map(f, x)
change [x for x in y] to list(y)

These changes reduce source code size and complexity and produce some minor performance gains

svn: r14104

src/UndoHistory.py

@@ -221,7 +221,7 @@ class UndoHistory(ManagedWindow.ManagedWindow):
             self.model.append(row=[time_text,mod_text,fg,bg])
 
         # Get the not-None portion of transaction list
-        translist = [item for item in self.undodb.translist if item]
+        translist = filter(None, self.undodb.translist)
         for transaction in translist:
             time_text = time.ctime(transaction.timestamp)
             mod_text = transaction.get_description()