自学教程：selenium在scrapy中的使用代码

import scrapyfrom selenium import webdriverfrom wangyiPro.items import WangyiproItemclass WangyiSpider(scrapy.Spider):    name = 'wangyi'    # allowed_domains = ['www.xxx.com']    start_urls = ['https://news.163.com/']    model_url = []       hro = webdriver.Chrome()    def parse(self, response):    # 从所有版块中筛选出所需要下载的4个版块        li_list = response.xpath('/html/body/div[1]/div[1]/div[2]/div[2]/div[2]/div[2]/div/ul/li')        indexs = [3,4,6,7]        for index in indexs:            model_li = li_list[index]            model_list = model_li.xpath('./a/@href').extract_first()            self.model_url.append(model_list)        for url in self.model_url:            yield scrapy.Request(url=url,callback=self.parse_model)    # 数据解析：新闻标题+新闻详情页的url（动态加载数据）    def parse_model(self,response):        # 直接对response解析无法获取该数据（动态加载数据）        # 无法拿到动态加载数据返回的响应数据就不足        # 使用中间件修改不满足需求的响应对象中的响应数据，将其改为包含动态加载数据的响应数据        div_list = response.xpath('/html/body/div/div[3]/div[4]/div[1]/div[1]/div/ul/li/div/div')        for div in div_list:            title = div.xpath('./div/div[1]/h3/a/text()').extract_first()            new_url_detail = div.xpath('./div/div[1]/h3/a/@href').extract_first()            if new_url_detail:                item = WangyiproItem()                item['title'] = title                yield scrapy.Request(url=new_url_detail,callback=self.parse_detail,meta={'item':item})    def parse_detail(self,response):        # 返回的列表，需要将其转换为字符串        content = response.xpath('/html/body/div[3]/div[1]/div[3]/div[2]/p/text()').extract()        content = ''.join(content)        item = response.meta['item']        item['content'] = content        yield item    # 重写爬虫类父类方法，该方法在爬虫程序执行结束后立即执行    def closed(self,spider):        # 打开selenium需要关闭        self.hro.quit()

from time import sleepfrom scrapy.http import HtmlResponse#scrapy封装好的响应类class WangyiproDownloaderMiddleware:    def process_request(self, request, spider):        return None    # 拦截所有的响应对象    # 整个工程发起的请求：1+4+n 对应相同的响应    def process_response(self, request, response, spider):        # 从所有拦截对象中找到4个需修改的响应对象        if request.url in spider.model_url:            hro = spider.hro            hro.get(request.url)            sleep(2)            # 网页下拉到底，获取更多动态加载数据            hro.execute_script('window.scrollTo(0,document.body.scrollHeight)')            sleep(1)            page_text = hro.page_source            # response.text = page_text            # 返回一个新的响应对象            return HtmlResponse(url=request.url,body=page_text,encoding='utf-8',request=request)        # 如果不是需要修改的响应数据，不做修改        else:            return response    def process_exception(self, request, exception, spider):        pass