def are_you_sure(listbox): popup = Toplevel() popup.title('AYS?') popup.geometry("200x80+1050+350") popup.resizable(False, False) label1 = Label(popup, text="Are you sure you want to reset?") cancel_button = Button(popup, text="Cancel", command=lambda: popup.destroy(), width=5) reset_ok = Button( popup, text="Reset", command=lambda: [MF.reset(listbox), popup.destroy()], width=5) label1.grid(row=0, column=0, columnspan=5, padx=(12, 0), pady=(7, 5)) cancel_button.grid(row=2, column=1, padx=(12, 6), pady=(5, 5)) reset_ok.grid(row=2, column=3, padx=(12, 0), pady=(5, 5)) popup.grab_set() popup.mainloop()