如何通过tk.Button获取开通函数的结果？

import tkinter as tk
root = tk.Tk()

def open_function():
    # 执行一些操作
    result = "开通成功"
    return result

button = tk.Button(root, text="开通", command=open_function)

result_label = tk.Label(root, text="")

def get_result():
    result = open_function()
    result_label.config(text=result)

get_result_button = tk.Button(root, text="获取结果", command=get_result)

button.pack()
result_label.pack()
get_result_button.pack()
root.mainloop()