Как запустить метод python в фоновом режиме?

#!/usr/bin/env python
# -*- coding: utf-8 -*-

from tkinter import *
from tkinter import messagebox as mb
import os


def start():
    import socket
    sock = socket.socket()
    sock.bind(('192.168.1.10', 9090))
    sock.listen(1)
    conn, addr = sock.accept()
    mb.showinfo("Conected", "---:" + str(addr))
    while True:
        data = conn.recv(10000)
        mb.showinfo("Send_", "---:" + str(data))
        print(data)
        if not data:
            break
    conn.send(data.upper())


root = Tk()
root.title("---")
lab1 = Label(root, text="---")
lab1.pack()
but1 = Button(root, text="---")
but1.pack()
but2 = Button(root, text="---", command=start)
but2.pack()

root.mainloop()

conn.close()