如何更新ttk.OptionsMenu中的下拉选项(python，tkinter，ttk)

import tkinter as tk
from tkinter import ttk

root = tk.Tk()

# 创建一个变量，用于存储选项的值
selected_option = tk.StringVar()

# 创建OptionsMenu小部件，并将其与变量绑定
options_menu = ttk.OptionMenu(root, selected_option, "Option 1", "Option 2", "Option 3")
options_menu.pack()

root.mainloop()

# 获取OptionsMenu的菜单
menu = options_menu['menu']

# 清空菜单中的选项
menu.delete(0, 'end')

# 添加新的选项
menu.add_command(label="New Option 1", command=lambda: selected_option.set("New Option 1"))
menu.add_command(label="New Option 2", command=lambda: selected_option.set("New Option 2"))
menu.add_command(label="New Option 3", command=lambda: selected_option.set("New Option 3"))

# 获取用户选择的选项的值
selected_value = selected_option.get()
print(selected_value)