from tkinter import *
from sys import exit
def popupError(s):
popupRoot = Tk()
popupRoot.after(2000, exit)
popupButton = Button(popupRoot, text = s, font = ("Verdana", 12), bg = "yellow", command = exit)
popupButton.pack()
popupRoot.geometry('400x50+700+500')
popupRoot.mainloop()