title: changing order of items in tkinter listbox
body: <p>Is there an easier way to change the order of items in a tkinter listbox than deleting the values for specific key, then re-entering new info?</p>
  
  <p>For example, I want to be able to re-arrange items in a listbox. If I want to swap the position of two, this is what I've done. It works, but I just want to see if there's a quicker way to do this.</p>
  
  <pre><code>def moveup(self,selection):
      value1 = int(selection[0]) - 1 #value to be moved down one position
      value2 = selection #value to be moved up one position
      nameAbove = self.fileListSorted.get(value1) #name to be moved down
      nameBelow = self.fileListSorted.get(value2) #name to be moved up
  
      self.fileListSorted.delete(value1,value1)
      self.fileListSorted.insert(value1,nameBelow)
      self.fileListSorted.delete(value2,value2)
      self.fileListSorted.insert(value2,nameAbove)
  </code></pre>