new_contents: import sys
  import zmq
  
  
  def main():
      # Get the arguments
      if len(sys.argv) != 2:
          print("Usage: sub.py url")
          sys.exit(1)
  
      url = sys.argv[1]
  
      context = zmq.Context()
      sock = context.socket(zmq.SUB)
      sock.setsockopt(zmq.SUBSCRIBE, b"")
      sock.connect(url)
  
      while True:
          msg = sock.recv_multipart()
          print(msg)
  
  if __name__ == "__main__":
      main()
  
subject: Add a subscriber example