loaders scrapy code example

Example 1: scrapy itemloader example

def parse_question(self, response):
        # ??question??? ??????????question item
        if "QuestionHeader-title" in response.text:
            # ?????
            match_obj = re.match("(.*zhihu.com/question/(\d+))(/|$).*", response.url)
            if match_obj:
                question_id = int(match_obj.group(2))

            item_loader = ItemLoader(item=ZhihuQuestionItem(), response=response)
            item_loader.add_css("title", "h1.QuestionHeader-title::text")
            item_loader.add_css("content", ".QuestionHeader-detail")
            item_loader.add_value("url", response.url)
            item_loader.add_value("zhihu_id", question_id)
            item_loader.add_css("answer_num", ".List-headerText span::text")
            item_loader.add_css("comments_num", ".QuestionHeader-Comment button::text")
            item_loader.add_css("watch_user_num", ".NumberBoard-value::text")
            item_loader.add_css("topics", ".QuestionHeader-topics .Popover div::text")

            question_item = item_loader.load_item()
        else:
            # ????????item??
            match_obj = re.match("(.*zhihu.com/question/(\d+))(/|$).*", response.url)

            if match_obj:
                question_id = int(match_obj.group(2))

            item_loader = ItemLoader(item=ZhihuQuestionItem(), response=response)
            # item_loader.add_css("title", ".zh-question-title h2 a::text")
            item_loader.add_xpath("title",
                                  "//*[@id='zh-question-title']/h2/a/text()|//*[@id='zh-question-title']/h2/span/text()")
            item_loader.add_css("content", "#zh-question-detail")
            item_loader.add_value("url", response.url)
            item_loader.add_value("zhihu_id", question_id)
            item_loader.add_css("answer_num", "#zh-question-answer-num::text")
            item_loader.add_css("comments_num", "#zh-question-meta-wrap a[name='addcomment']::text")
            # item_loader.add_css("watch_user_num", "#zh-question-side-header-wrap::text")
            item_loader.add_xpath("watch_user_num",
                                  "//*[@id='zh-question-side-header-wrap']/text()|//*[@class='zh-question-followers-sidebar']/div/a/strong/text()")
            item_loader.add_css("topics", ".zm-tag-editor-labels a::text")

            question_item = item_loader.load_item()

        yield scrapy.Request(self.start_answer_url.format(question_id, 20, 0), headers=self.headers,
                             callback=self.parse_answer)
        yield question_item

Example 2: scrapy itemloader example

def parse(self, response):
        l = ItemLoader(item=Area(), response=response)
        l.add_value('id', parse_qs(response.xpath('//div[@class="clearfix subnav level-1"]//li//a[2]/@href').extract()[0])['area_id'][0])
        l.add_xpath('name', '//div[@class="clearfix subnav level-1"]//li//a[2]/text()')
        l.add_value('updated', datetime.utcnow().isoformat()) # you can also use literal values
        return l.load_item()
        #self.log('URL: {}'.format(response.url))