def get_by_id(self, reply_id):
        '''
        Get the reply by id.
        '''
        reply = MReply.get_by_uid(reply_id)
        logger.info('get_reply: {0}'.format(reply_id))

        self.render('misc/reply/show_reply.html',
                    reply=reply,
                    username=reply.user_name,
                    date=reply.date,
                    vote=reply.vote,
                    uid=reply.uid,
                    userinfo=self.userinfo,
                    kwd={})
Get the reply by id.