title: Python modules not updating after restarting the main module
body: <p>I've recently come back to a project having had to stop for about 6 months, and after reinstalling my operating system and coming back to it I'm having all kinds of crazy things happen. I made sure to install the same version(2.6) of python that I was using before.</p>
  
  <p>It started by giving me strange tkinter error that I hadn't had trouble with before, the program is relatively simple and the 2 or 3 bugs that were left when i quit, I had documented and weren't related to the interface.</p>
  
  <p>Things got even weirder when the same error would pop up even after I had removed the offending section of code. In fact, the traceback pointed to a line that didn't even exist in the module it was referencing, eg: line 262 when the module was only 200 lines long. </p>
  
  <p>After just starting a completely new file for the main module and copy/pasting it finally recognized that the offending code was gone and I stopped getting the error only to find that any updates to the code I made in another module didn't show up when I restarted the program through the shell. (I didn't forget to save.) After fiddling with this, of course, the old interface error came back, only in a different section of code that had been working previously.</p>
  
  <p>In fact, if I revert back to the files I had six months ago, the program works fine. As soon as I change anything in the main module, however, the interface bug comes back.</p>
  
  <p>Here's the original error:</p>
  
  <pre><code>Exception in Tkinter callback
  Traceback (most recent call last):
    File "C:\Python26\lib\lib-tk\Tkinter.py", line 1410, in __call__
  return self.func(*args)
    File "C:\PyStuff\interface.py", line 202, in dispOne
  __main__.top.destroy()
    File "C:\Python26\lib\lib-tk\Tkinter.py", line 1938, in destroy
      self.tk.call('destroy', self._w)
  TclError: can't invoke "destroy" command:  application has been destroyed
  </code></pre>
  
  <p>I'm guessing something else is going on here other than my own poor programming. Anyone have any ideas?</p>
  
  <p>Edit: Thinking back, I believe I read something about it being a bad idea to run Tkinter programs through IDLE's shell, and it appears, at least, that the TclError has vanished if I instead start the main module by double clicking the .pyc file. Perhaps my problems were just a combination of that plus the timestamp/PYTHONPATH issues mentioned below by Chris Atlee and Vlad?</p>