Multithreading Python3. How to terminate script execution when the command to do so comes?

Question

Python

I am learning python. For training, I write a client-server. A lot of clients connect to the north, they communicate with it. But now the admin has connected to the server and he sends the command "adminexit" to the server to completely shut down the server. I tried to do it, but it does not work, the script does not end. Please tell me how to make it work.

#!/usr/bin/env python3
import socket
from threading import Thread, current_thread

host = "localhost"
port = 1605

sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
sock.bind((host, port))
sock.listen(5)
print("ready")
running=True

def clientthread(conn):
  while True:
    global running
    buf = conn.recv(1024)
    buf = buf.rstrip()
    if buf.decode('utf8') == "exit":
      conn.send(b"bye")
      break
    elif buf.decode('utf8') == "get":
      conn.send(b"data")
    elif buf.decode('utf8') == "adminexit":
      conn.send(b"EXIT!")
      running=False
      break
    else:
      conn.send(b"listen")

while True:	
  if running==True:
    conn, addr = sock.accept()
    print("client connected with address " + addr[0])
    conn.send(b"hello!")
    ht = Thread(target=clientthread, args=(conn,))
    ht.start()
  else:
    break
    
conn.close()
sock.close

Answer 1

import os
os._exit(0)