在tkinter中突出显示所选按钮

import tkinter as tk

window = tk.Tk()

selected_button = tk.IntVar()

button1 = tk.Radiobutton(window, text="按钮1", variable=selected_button, value=1)
button2 = tk.Radiobutton(window, text="按钮2", variable=selected_button, value=2)
button3 = tk.Radiobutton(window, text="按钮3", variable=selected_button, value=3)

button1.config(indicatoron=0, relief=tk.RAISED, bd=4)
button2.config(indicatoron=0, relief=tk.RAISED, bd=4)
button3.config(indicatoron=0, relief=tk.RAISED, bd=4)

button1.pack()
button2.pack()
button3.pack()

window.mainloop()