聊天程序，如何在python中实现多线程？

Question

我正在编写一个正在运行的聊天程序，但客户必须手动更新程序，例如使用空消息，以便查看其他人写的内容。为了解决这个问题，我想到了多线程。我该如何更改代码？

import socket
import select
import threading



HEADER_LENGTH = 10
IP = "0.0.0.0"
PORT = 46781

server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

server_socket.bind((IP, PORT))
server_socket.listen()

sockets_list = [server_socket]

clients = {}


def recieve_message(client_socket):
    try:
        message_header = client_socket.recv(HEADER_LENGTH)

        if not len(message_header):
            return False
        
        message_length = int(message_header.decode("utf-8").strip())
        return {"header": message_header, "data": client_socket.recv(message_length)}
    except:
        return False

while True:
    read_sockets, _, exception_sockets = select.select(sockets_list, [], sockets_list)

    for notified_socket in read_sockets:
        if notified_socket == server_socket:
            client_socket, client_address = server_socket.accept()

            user = recieve_message(client_socket)
            if user is False:
                continue
        
            sockets_list.append(client_socket)

            clients[client_socket] = user

            print(f"Accepted new connection from {client_address[0]}:{client_address[1]} username:{user['data'].decode('utf-8')}")

        else:
            message = recieve_message(notified_socket)

            if message is False:
                print(f"Closed connection from {clients[notified_socket]['data'].decode('utf-8')}")
                sockets_list.remove(notified_socket)
                del clients[notified_socket]
                continue

            user = clients[notified_socket]
            print(f"Recieved message from {user['data'].decode('utf-8')}: {message['data'].decode('utf-8')}")

            for client_socket in clients:
                if client_socket != notified_socket:
                    client_socket.send(user['header'] + user['data'] + message['header'] + message['data'])


    for notified_socket in exception_sockets:
        sockets_list.remove(notified_socket)
        del clients[notified_socket]

我试着自己做，但我完全失败了，因为 Python 不允许“正常”的多线程。