tkinter之radiobutton

from tkinter import *

root = Tk()

root.title('Test')
root.geometry('600x300')

var = StringVar()
l1 = Label(root, text='', width=30, height=1, bg='yellow', fg='red')
l1.pack()


def print_selection():
    l1.config(text=('you have selected ' + var.get()))
    pass


rb1 = Radiobutton(root, text='Option A', variable=var, value='A', command=print_selection)
rb1.pack()

rb2 = Radiobutton(root, text='Option B', variable=var, value='B', command=print_selection)
rb2.pack()

rb3 = Radiobutton(root, text='Option C', variable=var, value='C', command=print_selection)
rb3.pack()

root.mainloop()