Thread stoppen

class MyThread (threading.Thread):

    def run(self):

        print("start")

        a = 0

        while a < 100:

            a = a + 1

            print (a)

            time.sleep(1)

def button_action_start():    

    m = MyThread();

    m.start()

def button_action_stop():

    print("stop")

fenster = tk.Tk()

fenster.resizable(width=100,height=100)

start_button = Button(fenster, text="Start", command=button_action_start)

start_button.pack()    

stop_button = Button(fenster, text="Stop", command=button_action_stop)

stop_button.pack()

fenster.mainloop()