A single radio button performs the same basic function as a k.CheckButton, as its position in the object hierarchy reflects. It is only when multiple radio buttons are grouped together that they become a different user interface component in their own right.

Every radio button is a member of some group of radio buttons. When one is selected, all other radio buttons in the same group are deselected. A Gtk.RadioButton is one way of giving the user a choice from many options.

Radio button widgets are created with RadioButton(string), if this is the first radio button in a group. In subsequent calls, the group you wish to add this button to should be passed as an argument.