scrapy：从 xpath 选择器中删除一些元素

Question

我正在使用 Scrapy 抓取具有一些奇怪格式约定的网站。基本思想是我想要某个div的所有文本和子元素，除了中间的几个div。这是下面的代码：-

<div align="center" class="article"><!--wanted-->
    <img src="http://i.imgur.com/12345.jpg" width="500" alt="abcde" title="abcde"><br><br>     
    <div style="text-align:justify"><!--wanted-->
        Sample Text<br><br>Demo: <a href="http://www.example.com/?http://example.com/item/asash/asdas-asfasf-afaf.html" target="_blank">http://example.com/dfa/asfa/aasfa</a><br><br>
        <div class="quote"><!--wanted-->
            http://www.coolfiles.ro/download/kleo13.rar/1098750<br>http://www.ainecreator.com/files/0MKOGM6D/kleo13.rar_links<br>
        </div>
        <br>
        <div align="left"><!--not wanted-->
            <div id="ratig-layer-2249"><!--not wanted-->
                <div class="rating"><!--not wanted-->
                    <ul class="unit-rating">
                        <li class="current-rating" style="width:80%;">80</li>
                        <li><a href="#" title="Bad" class="r1-unit" onclick="doRate('1', '2249'); return false;">1</a></li>
                        <li><a href="#" title="Poor" class="r2-unit" onclick="doRate('2', '2249'); return false;">2</a></li>
                        <li><a href="#" title="Fair" class="r3-unit" onclick="doRate('3', '2249'); return false;">3</a></li>
                        <li><a href="#" title="Good" class="r4-unit" onclick="doRate('4', '2249'); return false;">4</a></li>
                        <li><a href="#" title="Excellent" class="r5-unit" onclick="doRate('5', '2249'); return false;">5</a></li>
                    </ul>
                </div>
                (votes: <span id="vote-num-id-2249">3</span>)
            </div>
        </div>
        <div class="reln"><!--not wanted-->
            <strong>
                <h4>Related News:</h4>
            </strong>
            <li><a href="http://www.example.com/themes/tf/a-b-c-d.html">1</a></li>
            <li><a href="http://www.example.com/plugins/codecanyon/a-b-c-d">2</a></li>
            <li><a href="http://www.example.com/themes/tf/a-b-c-d.html">3</a></li>
            <li><a href="http://www.example.com/plugins/codecanyon/a-b-c-d.html">4</a></li>
            <li><a href="http://www.example.com/plugins/codecanyon/a-b-c-d.html">5</a></li>
        </div>
    </div>
</div>

最终输出应如下所示：-

<div align="center" class="article"><!--wanted-->
    <img src="http://i.imgur.com/12345.jpg" width="500" alt="abcde" title="abcde"><br><br>     
    <div style="text-align:justify"><!--wanted-->
        Sample Text<br><br>Demo: <a href="http://www.example.com/?http://example.com/item/asash/asdas-asfasf-afaf.html" target="_blank">http://example.com/dfa/asfa/aasfa</a><br><br>
        <div class="quote"><!--wanted-->
            http://www.coolfiles.ro/download/kleo13.rar/1098750<br>http://www.ainecreator.com/files/0MKOGM6D/kleo13.rar_links<br>
        </div>
        <br>
    </div>
</div>

这是我的 Scrapy 代码。请建议添加到此脚本：-

from scrapy.contrib.spiders import CrawlSpider, Rule
from scrapy.contrib.linkextractors.sgml import SgmlLinkExtractor
from scrapy.selector import HtmlXPathSelector
from isbullshit.items import IsBullshitItem


class IsBullshitSpider(CrawlSpider):
    """ General configuration of the Crawl Spider """
    name = 'isbullshitwp'
    start_urls = ['http://example.com/themes'] # urls from which the spider will start crawling
    rules = [Rule(SgmlLinkExtractor(allow=[r'page/\d+']), follow=True), 
        # r'page/\d+' : regular expression for http://example.com/page/X URLs
        Rule(SgmlLinkExtractor(allow=[r'\w+']), callback='parse_blogpost')]
        # r'\d{4}/\d{2}/\w+' : regular expression for http://example.com/YYYY/MM/title URLs

    def parse_blogpost(self, response):
        hxs = HtmlXPathSelector(response)
        item = IsBullshitItem()
        item['title'] = hxs.select('//span[@class="storytitle"]/text()').extract()[0]
        item['article_html'] = hxs.select("//div[@class='article']").extract()[0]

        return item

以下是我尝试过但没有得到预期结果的以下 xpath：-

item['article_html'] = hxs.select("//div[@class='article']").extract()[0]
item['article_html'] = hxs.select("//div[@class='article']/following::node() [not(preceding::div[@class='reln']) and not(@class='reln')]").extract()[0]
item['article_html'] = hxs.select("//div[@class='article']/div[@class='reln']/preceding-sibling::node()[preceding-sibling::div[@class='quote']]").extract()[0]
item['article_html'] = hxs.select("//div[@class='article']/following::node() [not(preceding::div[@class='reln'])]").extract()[0]
item['article_html'] = hxs.select("//div[@class='article']/div[@class='quote']/*[not(self::div[@class='reln'])]").extract()[0]
item['article_html'] = hxs.select("//div[@class='article']/*[(self::name()='reln'])]").extract()[0]

提前谢谢...

Answer 1

使用 Scrapy，您似乎无法做到这一点。 我有自己的功能来删除特定节点（及其子节点）：

def removeNode(context, nodeToRemove):
    for element in nodeToRemove:
        contentToRemove = context.css(element)

        if contentToRemove:
            contentToRemove = contentToRemove[0].root
            contentToRemove.getparent().remove(contentToRemove)

    return context.extract()

希望对你有帮助