Tkinter - Radiobutton

INTRODUCTION

The 'Radiobutton' widget is used to create a single-choice interface. Pressing one widget in a group automatically deselects the one pressed last. Widgets in a group are associated with the same variable and a 'value' attribute is used when the button is selected.

# radio1.py
import tkinter as tk

root = tk.Tk()   # root widget

# The same variable for several radiobuttons is used.
var = tk.IntVar()   # a global variable is recommended
var.set(1)   # initializing the choice, i.e. Python

label = tk.Label(root, text="Choose a language:")
label.grid()

radio1 = tk.Radiobutton(root, text="Python", variable=var, value=1,
    command=lambda: print(var.get()))
radio1.grid(sticky=tk.W)

radio2 = tk.Radiobutton(root, text="Perl", variable=var, value=2,
    command=lambda: print(var.get()))
radio2.grid(sticky=tk.W)

radio3 = tk.Radiobutton(root, text="Java", variable=var, value=3,
    command=lambda: print(var.get()))
radio3.grid(sticky=tk.W)

root.mainloop()

Selected keyword arguments in Radiobutton()

master=root     # the first argument
text="text label"
textvariable=strvar   # an alternative to 'text'
width=50   # in text units
variable=var
command=lambda: print(var.get())
value=val   # value to use when that radiobutton is selected
padx=20
indicatoron=1   # (*) and the label (default)
indicatoron=0   # rectangle button with the label