Run 2to3 over the Demo/ directory to shut up parse errors from 2to3 about lingering print statements.
diff --git a/Demo/tkinter/matt/packer-and-placer-together.py b/Demo/tkinter/matt/packer-and-placer-together.py
index 184d56b..84d3ee0 100644
--- a/Demo/tkinter/matt/packer-and-placer-together.py
+++ b/Demo/tkinter/matt/packer-and-placer-together.py
@@ -8,7 +8,7 @@
     app.button.place(x=event.x, y=event.y)
 
 def dothis():
-    print 'calling me!'
+    print('calling me!')
 
 def createWidgets(top):
     # make a frame. Note that the widget is 200 x 200