[Tkinter] function to handle exception errors

[Larz60+]

you should only capture expected exceptions, If you're not sure what is getting thrown,
you can temporarily:

import sys
# add after line 15
        print("Unexpected error:", sys.exc_info()[0])
        raise

But once you're confident of the exceptions that you are getting, you should
change the except clause to be: 'except ValueError:' for example