def error(self, message):
        """error(message: string)

        Prints a usage message incorporating the message to stderr and
        exits.

        If you override this in a subclass, it should not return -- it
        should either exit or raise an exception.
        """
        self.print_usage(_sys.stderr)
        self.exit(2, _('%s: error: %s\n') % (self.prog, message))
def error ( self , message ) : self . print_usage ( _sys . stderr ) self . exit ( 2 , _ ( '%s: error: %s\n' ) % ( self . prog , message ) )
error(message: string)

        Prints a usage message incorporating the message to stderr and
        exits.

        If you override this in a subclass, it should not return -- it
        should either exit or raise an exception.