def _default_to(parser, dest, value):
 if (getattr(parser.values, dest) is None):
  setattr(parser.values, dest, value)

def _default_to ( parser , dest , value ) : if ( getattr ( parser . values , dest ) is None ) : setattr ( parser . values , dest , value )
helper function; set the given optino dest to *value* if its none .