tcp_echo_server.py

import socket
import sys
import argparse

host = 'localhost'
data_payload = 2048
backlog = 5

def echo_server(port):
    """ A simple echo server """
    # Create a TCP socket
    sock = socket.socket(socket.AF_INET,
                         socket.SOCK_STREAM)
    # Enable reuse address/port
    sock.setsockopt(socket.SOL_SOCKET,
                    socket.SO_REUSEADDR, 1)
    # Bind the socket to the port
    print(f"Starting up echo server on {host} port {port}")
    sock.bind((host, port))
    # Listen to clients, backlog argument specifies the max no.of queued connections
    sock.listen(backlog)
    while True:
        print("Waiting to receive message from client")
        client, address = sock.accept()
        data = client.recv(data_payload)
        if data:
            print(f"Data: {data.decode()}")
            client.send(data)
            print(f"sent {data.decode()} bytes back to {address}")
        # end connection
        client.close()


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description='Socket Server Example')
    parser.add_argument('--port', action="store",
                        dest="port", type=int, required=True)
    given_args = parser.parse_args()
    port = given_args.port
    echo_server(port)