XPath从IMG标签解析“SRC”？

Right now I successfully grabbed the full element from an HTML page with this:

现在我成功地从HTML页面抓取了完整的元素：

//img[@class='photo-large']

for example it would return this:

例如它会返回：

<img src="http://example.com/img.jpg" class='photo-large' />

But I only need the SRC url (http://example.com/img.jpg). Any help?

但我只需要SRC网址（http://example.com/img.jpg）。有帮助吗？

3 个解决方案

#1

You are so close to answering this yourself that I am somewhat reluctant to answer it for you. However, the following XPath should provide what you want (provided the source is XHTML, of course).

你是如此接近自己回答这个问题，我有点不愿意为你回答。但是，以下XPath应该提供您想要的（当然，如果源是XHTML）。

//img[@class='photo-large']/@src

For further tips, check out W3 Schools. They have excellent tutorials on such things and a great reference too.

有关更多提示，请查看W3学校。他们有关于这些事情的优秀教程，也是一个很好的参考。

#2

Using Hpricot this works:

使用Hpricot这有效：

doc.at('//img[@class="photo-large"]')['src']

In case you have more than one image, the following gives an array:

如果您有多个图像，下面给出一个数组：

doc.search('//img[@class="photo-large"]').map do |e| e['src'] end

However, Nokogiri is many times faster and it “can be used as a drop in replacement” for Hpricot.
Here the version for Nokogiri, in which this XPath for selecting attributes works:

然而，Nokogiri的速度要快很多倍，它可以用作Hpricot的替代品。这里是Nokogiri的版本，其中用于选择属性的XPath工作：

doc.at('//img[@class="photo-large"]/@src').to_s

or for many images:

或许多图像：

doc.search('//img[@class="photo-large"]/@src').to_a

#3

//img/@src

// IMG / @ SRC

you can just go with this if you want a link of the image.

如果你想要一个图像的链接，你可以使用它。

example:

例：

<img alt="" class="avatar width-full rounded-2" height="230" src="https://avatars3.githubusercontent.com/...;s=460" width="230">

#1