Tkinter weirdness item count

[phil]

> I seem to remember a thread a while ago about a 'bug' with the Tk Canvas
> widget keeping a reference to objects that had been deleted...
> 
> Have you thought about using the 'move' method to move your lines?  I 
> think this will result in less supprises...
> 

Actually I solved that problem. My bug. It does delete the objects.

My current problem, in another post, is that when I draw thousands
of objects plotting complex functions, the drawing gets really slow.

If I draw 12000 points and then return to mainloop it takes 2 seconds.

If I draw each point then call update_idletasks() it takes about 60
seconds.  It goes very fast at first and gradually gets slower.