python chat app - server

import socket
import threading
from tkinter import *
from tkinter import scrolledtext
root = Tk()
root.geometry("650x390")
output = scrolledtext.ScrolledText(root, wrap = WORD, bg='black', fg="lime", font = (13))
output.pack()

server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
firstTime = True
PORT = 8080
SERVER = '192.168.1.6'
print(SERVER)
ADDR = (SERVER, PORT)
FORMAT = 'utf-8'
CLIENTS = set()
CLIENTSA = 0

server.bind(ADDR)

def handle_client(conn, addr):
    global CLIENTS
    global CLIENTSA
    global firstTime
    output.insert(INSERT, "\n ACTIVE CLIENTS: %s" %CLIENTSA)
    output.insert(INSERT,f'\n[NEW CONNECTION] {addr} connected')
    connected = True
    while connected:
        try:
            msg = conn.recv(1024)
            output.insert(INSERT," \n[CLIENT] " + msg.decode(FORMAT))
            print("got msg: " + msg.decode())
            for client in CLIENTS:
                print(msg.decode(FORMAT).split(","))
                if "FirstTime" in msg.decode(FORMAT).split(','):
                    message = msg.decode(FORMAT).split(',')[1] + " Joined the Cave"
                    client.send(message.encode(FORMAT))
                    output.insert(INSERT, f"\n{message}")
                else:
                    client.send(msg)
                    output.insert(INSERT, "\nmessage send")
        except:
            conn.close()
            output.insert(INSERT, "\nCLIENT LEFT")
            CLIENTSA -= 1
            break

def start():
    global CLIENTSA
    output.insert(INSERT,'SERVER STARTED')
    server.listen()
    while True:
        conn, addr = server.accept()
        thread = threading.Thread(target=handle_client,args=(conn,addr), daemon=True)
        CLIENTS.add(conn)
        CLIENTSA += 1
        thread.start()

startThread = threading.Thread(target=start, daemon=True)
startThread.start()
root.mainloop()