Simple string describing the action.

def about_action(self):
        """ Simple string describing the action. """
        name = self.action.metavar or self.action.dest
        type_name = self.action.type.__name__ if self.action.type else ''
        if self.action.help or type_name:
            extra = ' (%s)' % (self.action.help or 'type: %s' % type_name)
        else:
            extra = ''
        return name + extra