title: Using a single telnet session in two different methods
body: <p>I need to use a telnet session like in this code below :</p>
  
  <pre><code>class ModTelnet(MXComm):
  def __init__(self):
      MXComm.__init__(self)
  
  def _connect(self):
      #connect to telnet session @ localhost port 4444
      try:
          HOST = "localhost"
          port = "4444"
       #   tn = telnetlib.Telnet(HOST, port)
          tn.open(HOST, port)
      except:
          print "Connection refused"
  
  
  def _receive(self):
      #receive data (= msg) from telnet stdout
      try:
          data = tn.read_all()
          return data
      except tn.eof.ERR as ex:
          if 'timeout error' not in ex.args[0]:
              print 'Connection error:', ex 
              raise Disconnected()
  
  def _send(self, data):
      #send command to telnet session
      try:          
          tn.write(data + "\n")
      except tn.socket.error as ex:
          if 'timeout error' not in ex.args[0]:
              print 'Connection error:', ex 
              raise Disconnected()
  </code></pre>
  
  <p>Here ise the error raised :</p>
  
  <pre><code>QApplication: Invalid Display* argument
  Connection refused
  Exception in thread Thread-1:
  Traceback (most recent call last):
    File "/usr/lib/python2.6/threading.py", line 532, in __bootstrap_inner
      self.run()
    File "/home/mk3/MODiMX27/PELM_Gui/src/modimx.py", line 188, in run
      self._conn.try_get_data()
    File "/home/mk3/MODiMX27/PELM_Gui/src/modimx.py", line 58, in try_get_data
      rx_item = self._receive()
    File "/home/mk3/MODiMX27/PELM_Gui/src/modimx.py", line 112, in _receive
      except tn.eof.ERR as ex:
  
  NameError: global name 'tn' is not defined
  </code></pre>
  
  <p>The problem is that it seems to not recognize the telnet session open in my first method "connect"...How can we do this the best way?</p>