wxPython default radiobox choice

[crystalattice]

In my GUI app, I have a radio box allowing the user to pick his/her
gender.  When I click a button, I'd like the radio box to tell the
program which choice is marked.  I can get it to work when I manually
pick a choice but I get an error when the choice is left at the default
value, which is "Male".

I have the radio box tied to an event to "see" when a choice is made,
but how does it work if the person just leaves the default value?  I've
looked at the wxPython demo but the radio box actions only work for
changing values.