I have two questions regarding tkinter that I cant seem to find the answer too. 
1) I currently have 2 radio buttons. I have programmed them in such a way that when one of them is clicked another definition is called and that creates a regular button on the screen. Now my problem is, if the user toggles between the both radio buttons, each time a new button will be created (instead of just having 1 the first time he toggles the options). Is there any way I can stop the extra buttons from being created if one already exsists?
2) Is there a widget that can easily be used to create check box lists?
EDIT: Sorry, I meant check box list not radio button list.
1> Define you button outside the eventHandler of the radiobutton. 
inside the event handler only grid/pack it,whenever the radiobutton is pressed. In this way the button will not be defined multiple times.
N.B. Use fix row & column with the grid if you need.
Doubts about checking if button is already displayed and making a list of radio buttons