XPath 查询查找不在选择器内的元素

Question

我的 XPath 查询正在查找甚至不在其中的元素。例如（来自我下面的代码）business_div 包含 HTML:

<div class="foo">
    <div>
       <table>
          ...
          <a class="bar" href="A">link</a>
       </table>
    </div>
</div>

当我运行 XPath 查询 business_div.xpath("//a[@class='bar']/@href").extract() 它 returns:

["A", "B", "D"] # should just be ["A"]

我如何才能查询 business_div 以获得 "A"？

<div class="foo">
    <div>
       <table>
          ...
          <a class="bar" href="A">link</a>
       </table>
    </div>
</div>

<div class="foo">
    <div>
       <table>
          ...
          <a class="bar" href="B">link</a>
       </table>
    </div>
</div>

<div class="foo">
    <div>
       <table>
          ...
          <!-- Some divs will not contain a link. So I cant do a simple query "//div[contains(@class, "foo")]//a[contains(@class, "bar")]/@href" -->
       </table>
    </div>
</div>

<div class="foo">
    <div>
       <table>
          ...
          <a class="bar" href="D">link</a>
       </table>
    </div>
</div>

我的代码：

class MySpider(CrawlSpider):

    name = "MySpider"
    ...

    def parse(self, response):
        businesses = []
        business_divs = response.xpath("//div[contains(@class, 'foo')]")

        for business_div in business_divs:
            business = MyItem()
            business["link"] = business_div.xpath("//a[@class='bar']/@href").extract()

            # business["link"] is ["A", "B", "D"]
            # I am expecting business["link"] to simply be ["A"] 
            # in the first loop then ["B"] and so on

Answer 1

稍微改变一下 xpath 就可以解决问题，

business["link"] = business_div.xpath(".//a[@class='bar']/@href").extract()

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