from tkinter import messagebox, NORMAL # noinspection PyProtectedMember class GUIFuncs: def __init__(self, gui): self.gui = gui def show_error(self, error): self.gui.call_in_thread(lambda: messagebox.showerror("ERROR", error)) def bot_started(self, started): def func(): self.gui._bot_running = started self.gui._start_button["text"] = "STOP" if self.gui._bot_running else "START" self.gui.call_in_thread(func)