title: Python Tkinter - get selection on Radiobutton
body: <p>I need to retrieve the value of Radiobutton clicked and then use this value .</p>
  
  <p>What is the way to retrieve the value of a Radiobutton clicked ?</p>
  
  <p>the code to setup the Radiobutton is:</p>
  
  <pre><code>radio_uno = Radiobutton(Main,text='Config1', value=1,variable = 1)
  radio_uno.pack(anchor=W,side=TOP,padx=3,pady=3)
  radio_due = Radiobutton(Main,text='Config2', value=2,variable =1)
  radio_due.pack(anchor=W,side=TOP,padx=3,pady=3)
  radio_tre = Radiobutton(Main,text='Config3', value=3,variable = 1)
  radio_tre.pack(anchor=W,side=TOP,padx=3,pady=3)
  </code></pre>