wxPython: Threading GUI --> Using Custom Event Handler

Question

I am trying to learn how to run a thread off the main GUI app to do my serial port sending/receiving while keeping my GUI alive. My best Googling attempts have landed me at the

Answer 1

You may want to use Python threads and queues and not custom events. I have a wxPython program (OpenSTV) that loads large files that caused the gui to freeze during the loading. To prevent the freezing, I dispatch a thread to load the file and use a queue to communicate between the gui and the thread (e.g., to communicate an exception to the GUI).

  def loadBallots(self):
    self.dirtyBallots = Ballots()
    self.dirtyBallots.exceptionQueue = Queue(1)
    loadThread = Thread(target=self.dirtyBallots.loadUnknown, args=(self.filename,))
    loadThread.start()

    # Display a progress dialog
    dlg = wx.ProgressDialog(\
      "Loading ballots",
      "Loading ballots from %s\nNumber of ballots: %d" % 
      (os.path.basename(self.filename), self.dirtyBallots.numBallots),
      parent=self.frame, style = wx.PD_APP_MODAL | wx.PD_ELAPSED_TIME
    )
    while loadThread.isAlive():
      sleep(0.1)
      dlg.Pulse("Loading ballots from %s\nNumber of ballots: %d" %
                (os.path.basename(self.filename), self.dirtyBallots.numBallots))
    dlg.Destroy()

if not self.dirtyBallots.exceptionQueue.empty():
  raise RuntimeError(self.dirtyBallots.exceptionQueue.get())