Default argument for an option?

This has probably been asked before but I couldn't find the answer:
is it possible to have a default argument for a switch?

I have this code:

add_option('-g',
           '--guistyle',
            action  = 'store',
            dest    = 'guistyle',
            metavar = 'STYLE',
            nargs   = 1,
            type    = 'string',
            help    = 'graphical output (STYLE = none|gnome|kde|windows)')

I would like this option argument default to 'none' (which means use
Tcl/Tk EasyGui) so it would be possible to use it like
foobar --guistyle none
and
foobar --guistyle

The option itself shouldn't default to "--guistyle none"; only if
--guistyle is given on the command line.

Is this possible with Optik?

Thorsten



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