[PYTHON] Chat creation using sockets

You can find a python chat program on the command line that is not a web app. However, none of them (those that can input asynchronously) work on Windows. For the time being, I made something that works, so I will publish it.

Server program

Start as "python server.py IP address"

server.py

import sys, socket, select
 
def broadcast(socklist, server_socket, sock, message):
    print(message)
    for socket in socklist:
        if socket != server_socket and socket != sock :
            try :
                socket.send(message.encode())
            except :
                socket.close()
                socklist.remove(socket)
 
if __name__ == '__main__':
    port, socklist, server = 5001, [], '127.0.0.1' if len(sys.argv) <= 1 else sys.argv[1]
    server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server_socket.bind((server, port))
    server_socket.listen(10)
    socklist.append(server_socket)
    print('Start')
    while True:
        read_sockets, write_sockets, error_sockets = select.select(socklist, [], [])
        for sock in read_sockets:
            if sock == server_socket:
                sockfd, addr = server_socket.accept()
                socklist.append(sockfd)
                broadcast(socklist, server_socket, sockfd, '[%s:%s] Enter' % addr)
            else:
                try:
                    data = sock.recv(4096).decode()
                    if data == '': raise Exception('Done')
                    if data:
                        broadcast(socklist, server_socket, sock, data)                
                except Exception as e:
                    print(e)
                    broadcast(socklist, server_socket, sock, '[%s, %s] Exit' % addr)
                    sock.close()
                    socklist.remove(sock)

Client program

Run as "python client.py username IP address"

client.py

import sys, socket, select, threading
 
def prompt(user) :
    sys.stdout.write('%s> ' % user)
    sys.stdout.flush()
 
if __name__ == "__main__":
    if len(sys.argv) < 3:
        print('Usage : python %s user host' % sys.argv[0])
        sys.exit()
    (user, host), port = sys.argv[1:3], 5001
    server_sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try :
        server_sock.connect((host, port))
    except :
        print('Unable to connect')
        sys.exit()
    print('Start')
    def listen():
        while True:
            read_sockets, write_sockets, error_sockets = select.select([server_sock], [], [])
            try:
                data = server_sock.recv(4096).decode()
            except:
                break
            sys.stdout.write('\r%s\n' % data)
            prompt(user)
        print('\rTerminated')
    t = threading.Thread(target=listen)
    t.start()
    prompt(user)
    while True:
        msg = sys.stdin.readline().strip()
        if not msg:
            server_sock.close()
            break
        try:
            server_sock.send(('%s| %s' % (user, msg)).encode())
        except:
            break
        prompt(user)

In Python2 series, only ASCII is OK.