使用scrapy刮网站

时间:2013-05-15 08:12:34

标签: python html scrapy

我正在尝试使用scrapy刮取website,但我在使用无限滚动时从该网站抓取所有产品时遇到问题...

我只能在52项以下的数据下面搜索,但它们是3824项。

hxs.select("//span[@class='itm-Catbrand strong']").extract()
hxs.select("//span[@class='itm-price ']").extract()
hxs.select("//span[@class='itm-title']").extract()

如果我使用hxs.select("//div[@id='content']/div/div/div").extract()然后它会提取整个项目列表但不会进一步过滤....我如何刮掉所有项目?

我试过这个但结果相同。我哪里错了?

def parse(self, response):
    filename = response.url.split("/")[-2]
    open(filename, 'wb').write(response.body
    for n in [2,3,4,5,6]:            
    req = Request(url="http://www.jabong.com/men/shoes/?page=" + n,
                      headers = {"Referer": "http://www.jabong.com/men/shoes/",
                                 "X-Requested-With": response.header['X-Requested-With']})
    return req 

1 个答案:

答案 0 :(得分:5)

正如您所猜测的,当您滚动时,此网站使用javascript加载更多项目 页。

使用浏览器中包含的开发人员工具(Ctrl-Maj i for chromium),我在网络选项卡中看到页面中包含的javascript脚本执行以下请求以加载更多项目:

GET http://www.website-your-are-crawling.com/men/shoes/?page=2 # 2,3,4,5,6 etc...

Web服务器使用以下类型的文档进行响应:

<li id="PH969SH70HPTINDFAS" class="itm hasOverlay unit size1of4 ">
  <div id="qa-quick-view-btn" class="quickviewZoom itm-quickview ui-buttonQuickview l-absolute pos-t" title="Quick View" data-url ="phosphorus-Black-Moccasins-233629.html" data-sku="PH969SH70HPTINDFAS" onClick="_gaq.push(['_trackEvent', 'BadgeQV','Shown','OFFER INSIDE']);">Quick view</div>

                                    <div class="itm-qlInsert tooltip-qlist  highlightStar"
                     onclick="javascript:Rocket.QuickList.insert('PH969SH70HPTINDFAS', 'catalog');
                                             return false;" >
                                              <div class="starHrMsg">
                         <span class="starHrMsgArrow">&nbsp;</span>
                         Save for later                         </div>
                                        </div>
                <a id='cat_105_PH969SH70HPTINDFAS' class="itm-link sobrTxt" href="/phosphorus-Black-Moccasins-233629.html" 
                                    onclick="fireGaq('_trackEvent', 'Catalog to PDP', 'men--Shoes--Moccasins', 'PH969SH70HPTINDFAS--1699.00--', this),fireGaq('_trackEvent', 'BadgePDP','Shown','OFFER INSIDE', this);">
                    <span class="lazyImage">
                        <span style="width:176px;height:255px;" class="itm-imageWrapper itm-imageWrapper-PH969SH70HPTINDFAS" id="http://static4.jassets.com/p/Phosphorus-Black-Moccasins-6668-926332-1-catalog.jpg" itm-img-width="176" itm-img-height="255" itm-img-sprites="4">
                            <noscript><img src="http://static4.jassets.com/p/Phosphorus-Black-Moccasins-6668-926332-1-catalog.jpg" width="176" height="255" class="itm-img"></noscript>
                        </span>                            
                    </span>

                                            <span class="itm-budgeFlag offInside"><span class="flagBrdLeft"></span>OFFER INSIDE</span>                       
                                            <span class="itm-Catbrand strong">Phosphorus</span>
                    <span class="itm-title">
                                                                                Black Moccasins                        </span>

这些文件包含更多项目。

因此,要获取完整的项目列表,您必须在Spider的Request方法中返回parse个对象(请参阅Spider class documentation),告诉scrapy它应该加载更多数据:

def parse(self, response):
    # ... Extract items in the page using extractors
    n = number of the next "page" to parse
    # You get get n by using response.url, extracting the number
    # at the end and adding 1

    # It is VERY IMPORTANT to set the Referer and X-Requested-With headers
    # here because that's how the website detects if the request was made by javascript
    # or direcly by following a link.
    req = Request(url="http://www.website-your-are-crawling.com/men/shoes/?page=" + n,
       headers = {"Referer": "http://www.website-your-are-crawling.com/men/shoes/",
          "X-Requested-With": "XMLHttpRequest"})
    return req # and your items

哦,顺便说一句(如果你想测试),你不能只在你的浏览器中加载http://www.website-your-are-crawling.com/men/shoes/?page=2以查看它返回的内容,因为网站会将你重定向到全局页面(即{ {1}})如果http://www.website-your-are-crawling.com/men/shoes/标题与X-Requested-With不同。