"continously-running" Tornado TCP client example -- sends to 'tornado/demos/tcpecho/server.py'

tcpclient.py

import time
import logging
from tornado.options import options, define
from tornado import gen
from tornado.tcpclient import TCPClient
from tornado.iostream import StreamClosedError
from tornado.ioloop import IOLoop

define("host", default="127.0.0.1", help="TCP server host")
define("port", default=9888, help="TCP port to connect to")
define("sleep_for", default=2.0, help="Sleep time before next message-send")
define("delay", default=1.5, help="delay for re(run) callback")

logger = logging.getLogger(__name__)


class EchoClient(TCPClient):
    """ 
    "continously-running" TCP client - sends to 'tornado/demos/tcpecho/server.py'
    Derived from: tornado/demos/tcpecho/client.py
    
    """

    def get_random_word(self, length=10):
        """ kudos to StackOverflow...
        """
        import random

        random_word = ""
        for i in range(length):
            random_word += (str(chr(random.randint(97,122))))
        return random_word

    @gen.coroutine
    def run(self, loop, service=None):
        logger.info("in EchoClient.run() ...")

        if service is None:
            service = yield TCPClient().connect(options.host, options.port)

        try:
            our_msg_bytes = self.get_random_word() +'\n'
            yield service.write(our_msg_bytes.encode())
            logger.info("Sent to server: {}".format(our_msg_bytes.strip()))

            data = yield service.read_until(b"\n")
            logger.info("Response: %s", data.decode().strip())
        except StreamClosedError:
            logger.warning("Lost our server at host %s", options.host)
            loop.stop()
        except Exception as e:
            print(e)

        # reschedule.me!
        loop.call_later(options.delay, self.run, loop, service)


if __name__ == "__main__":
    options.parse_command_line()
    # import pdb; pdb.set_trace()
    # pp options.as_dict()
    client = EchoClient()
    logger.info("Sending data on TCP port %d", options.port)
    loop = IOLoop.current()
    loop.call_later(options.delay, client.run, loop)
    loop.start()