root = Tk()
root.title('app')
screen_width = root.winfo_screenwidth()
screen_height = root.winfo_screenheight()
root.geometry('550x250+%d+%d' % (screen_width / 2 - 275, screen_height / 2 -
    125))
root.configure(background='gold')
root.lift()
mainloop()
How to put a Tkinter window on top of the others