Code snippet below. I'm providing a small scenario.
import tkinter as tk
from tkinter import *
root = Tk()
def exit():
if askokcancel("Quit", "Do you really want to quit?"):
root.destroy()
menubar = Menu(root, background='#000099', foreground='white',
activebackground='#004c99', activeforeground='white')
fileMenu = Menu(menubar, tearoff=0, background="grey", foreground='black',
activebackground='#004c99', activeforeground='white')
menubar.add_cascade(label='File', menu=fileMenu)
fileMenu.add_command(label='Exit', command=exit)
root.config(bg='#2A2C2B',menu=menubar)
if __name__ == '__main__':
root.mainloop()
I have created a blank window here & add file menu option on the same window(root window), where I only add one option exit.
Then simply run mainloop for root.
Try to do it once