在tkinter中默认选择单选按钮

import tkinter as tk

root = tk.Tk()

# 创建一个变量，用于存储选择的单选按钮的值
selected_option = tk.StringVar()

# 创建单选按钮
option1 = tk.Radiobutton(root, text="Option 1", variable=selected_option, value="option1")
option2 = tk.Radiobutton(root, text="Option 2", variable=selected_option, value="option2")
option3 = tk.Radiobutton(root, text="Option 3", variable=selected_option, value="option3")

# 设置默认选择的单选按钮
selected_option.set("option2")

# 将单选按钮添加到窗口中
option1.pack()
option2.pack()
option3.pack()

root.mainloop()