如何让python程序重新启动并关闭现有的tkinter窗口？

import sys
import os
import tkinter as tk

def close_window():
    root.destroy()

def restart_program():
    python = sys.executable
    os.execl(python, python, *sys.argv)

root = tk.Tk()

close_button = tk.Button(root, text="关闭", command=close_window)
close_button.pack()

restart_button = tk.Button(root, text="重新启动", command=restart_program)
restart_button.pack()

root.mainloop()