text: # This is the Twisted Get Poetry Now! client, version 4.0
  
  import optparse, sys
  
  from twisted.internet import defer
  from twisted.internet.protocol import Protocol, ClientFactory
  
  def TimeoutError(Exception):
      print "We timeout out!"
      pass
  
  
  def parse_args():
      usage = """usage: %prog [options] [hostname]:port ...
  
  This is the Get Poetry Now! client, Twisted version 4.0
  Run it like this:
  
    python get-poetry.py port1 port2 port3 ...
  
  If you are in the base directory of the twisted-intro package,
  you could run it like this:
  
    python twisted-client-4/get-poetry.py 10001 10002 10003
  
  to grab poetry from servers on ports 10001, 10002, and 10003.
  
  Of course, there need to be servers listening on those ports
  for that to work.
  """
  
      parser = optparse.OptionParser(usage)
  
      _, addresses = parser.parse_args()
  
      if not addresses:
          print parser.format_help()
          parser.exit()
  
      def parse_address(addr):
          if ':' not in addr:
              host = '127.0.0.1'
              port = addr
          else:
              host, port = addr.split(':', 1)
  
          if not port.isdigit():
              parser.error('Ports must be integers.')
  
          return host, int(port)
  
      return map(parse_address, addresses)
  
  
  class PoetryProtocol(Protocol):
  
      poem = ''
  
      def dataReceived(self, data):
          print "received {}".format(data)
          self.poem += data
  
      def connectionLost(self, reason):
          self.poemReceived(self.poem)
  
      def poemReceived(self, poem):
          self.factory.poem_finished(poem)
  
  
  class PoetryClientFactory(ClientFactory):
  
      protocol = PoetryProtocol
  
      def __init__(self, deferred):
          self.deferred = deferred
  
      def startedConnecting(self, connector):
          from twisted.internet import reactor
          self.timeout_call = reactor.callLater(1, self.handle_timeout, connector)
  
      def poem_finished(self, poem):
          if self.deferred is not None:
              d, self.deferred = self.deferred, None
              d.callback(poem)
  
      def clientConnectionFailed(self, connector, reason):
          self.timeout_call.cancel()
  
          if self.deferred is not None:
              d, self.deferred = self.deferred, None
              d.errback(reason)
  
      def handle_timeout(self, connector):
          if self.deferred is not None:
              d, self.deferred = self.deferred, None
              connector.disconnect()
              d.errback(TimeoutError)
  
  
  
  
  def get_poetry(host, port):
      """
      Download a poem from the given host and port. This function
      returns a Deferred which will be fired with the complete text of
      the poem or a Failure if the poem could not be downloaded.
      """
      d = defer.Deferred()
      from twisted.internet import reactor
      factory = PoetryClientFactory(d)
      reactor.connectTCP(host, port, factory)
      return d
  
  
  def poetry_main():
      addresses = parse_args()
  
      from twisted.internet import reactor
  
      poems = []
      errors = []
  
      def got_poem(poem):
          poems.append(poem)
  
      def poem_failed(err):
          print >>sys.stderr, 'Poem failed:', err
          print >>sys.stderr, 'From {} on port {}'.format(host, port)
          errors.append(err)
  
      def poem_done(_):
          if len(poems) + len(errors) == len(addresses):
              reactor.stop()
  
      for address in addresses:
          host, port = address
          d = get_poetry(host, port)
          d.addCallback(got_poem)
          d.addErrback(poem_failed)
          d.addBoth(poem_done)
  
      reactor.run()
  
      for poem in poems:
          print poem
  
  
  if __name__ == '__main__':
      poetry_main()
  