jtl_str = topic_info.xpath(".//div[@class='close_topic']/text()").extract()[0]
            jtl = 0.0
            jtl_match = re.search("(\d+\.*\d*)", jtl_str)
            if jtl_match:
                jtl = jtl_match.group(1)

            existed_topic = Topic.select().where(Topic.id == topic_id)
            if existed_topic:
                topic = existed_topic[0]
                topic.content = content
                topic.praised_nums = int(praised_nums)
                topic.jtl = float(jtl)
                topic.save()

老师这个地方在Scrapy中怎么实现???不会,不会,不会啊!!! 怎么获取 topic_item = TopicItem() .将content,jtl,praised_nums 保存