multithreading - Python app with tkinter and threading error at closing -

i writing software project homework, having trouble mixing threads , tkinter. following piece works expected, when close (after starting in python shell), windows shows error: "python stopped working".

import threading import time import tkinter import tkinter.ttk  class btclient:     def __init__(self, master):         self.root = master         self.root.bind("<destroy>", self.on_destroy)          self.t = threading.thread(target=self.update)         self.running = false      def on_destroy(self, event):         self.running = false      def run_thread(self):         self.running = true         self.t.start()      def update(self):         while self.running:             print("update.")             time.sleep(1)  def main(args):     root = tkinter.tk()     client = btclient(root)     client.run_thread()     root.mainloop()  if __name__ == "__main__":     import sys     main(sys.argv) 

how can solve problem? caused design using? should change it?

edit 1: when remove self.root declaration in __init__ , use master reference problem solved, need have references gui objects, first build gui , input them, don't know how solve that. maybe passing objects arguments may need them?

its hard know whats happening without seeing actual code, make threaded method function outside of btclient , move thread outside of client , add call thread.join() after mainloop have thread finish cleanup before btclient deleted gc

def update():     import time     while thread._keep_alive:         time.sleep(1)         print("thread running")  thread = threading.thread(target=update) thread._keep_alive = true thread.start() 

at end

thread._keep_alive = false thread.join()