Run 2to3 over the Demo/ directory to shut up parse errors from 2to3 about lingering print statements.
diff --git a/Demo/tix/tixwidgets.py b/Demo/tix/tixwidgets.py
index bf7102a..49d1e7f 100644
--- a/Demo/tix/tixwidgets.py
+++ b/Demo/tix/tixwidgets.py
@@ -166,7 +166,7 @@
                 try: tkMessageBox.showerror ('Error', text)
                 except: pass
                 self.exit = 1
-                raise SystemExit, 1
+                raise SystemExit(1)
 
     def destroy (self):
         self.root.destroy()