title: Tkinter window says (not responding) but code is running
body: <p>I have a program that runs a long process after you click an action button.  As the process is running the root window will say that it is not responding even though I know the program is running in the background.  This program is going to be released to a few people that I work with and I want to make sure they don't freak out and close the window when they see this.  The solution I have is sitting a root.update in the loop of the process that is running but I am not sure this was the best fix.</p>
  
  <p>Using the python 3.3 </p>
  
  <p>Here is a sample of the code so you get an idea of what I am doing, this is called from the main loop:</p>
  
  <pre><code>def combine(boxes_to, boxes_from, frame):
          to_value,to_pos = gui.checkBoxes(boxes_to)
          from_value,from_pos = gui.checkBoxes(boxes_from)
          frame.destroy()
  
          running = Label(root,text="Running please do not close..",font = (16))
          running.pack()
          root.update()
          map_to = open("map_to",'r')
          for line in map_to:
              root.update()
              process(line)
  
  
          running.destroy()
          map_to.close()
          finish = Button(root, text="Done",command=gui.stop)
          finish.pack()
  </code></pre>