Tkinter:如何处理包含多个菜单项的菜单？

import tkinter as tk

root = tk.Tk()

menu_bar = tk.Menu(root)
root.config(menu=menu_bar)

file_menu = tk.Menu(menu_bar)
menu_bar.add_cascade(label="File", menu=file_menu)

file_menu.add_command(label="Open", command=open_file)
file_menu.add_command(label="Save", command=save_file)

def open_file():
    # 处理打开文件的逻辑

def save_file():
    # 处理保存文件的逻辑

import tkinter as tk

def open_file():
    print("Open file")

def save_file():
    print("Save file")

root = tk.Tk()

menu_bar = tk.Menu(root)
root.config(menu=menu_bar)

file_menu = tk.Menu(menu_bar)
menu_bar.add_cascade(label="File", menu=file_menu)

file_menu.add_command(label="Open", command=open_file)
file_menu.add_command(label="Save", command=save_file)

root.mainloop()