XPath 查询：从标签中获取属性 href
[英]XPath Query: get attribute href from a tag
问题描述
I want to use XPath to get the href attribute from an a -tag, but it has two occurrences within the same file.
我想使用 XPath 从a -tag 获取href属性，但它在同一个文件中出现了两次。 How am I getting along?我相处得怎么样？ I need to check IF there is an href attribute with value $street/object, I have got this code and it does not work:我需要检查是否有一个值为 $street/object 的href属性，我有这个代码但它不起作用：
$product_photo = $xpath->query("//a[contains(@href,'{$object_street}fotos/')][1]");
$product_360 = $xpath->query("//a[contains(@href,'{$object_street}360-fotos/')][1]");
$product_blueprint = $xpath->query("//a[contains(@href,'{$object_street}plattegrond/')][1]");
$product_video = $xpath->query("//a[contains(@href,'{$object_street}video/')][1]");
It does not return anything at all.它根本不返回任何东西。 Who can help me out?谁能帮帮我？
2 个解决方案
解决方案1
101 已采纳 2014-01-30 11:42:15
For the following HTML document:对于以下 HTML 文档：
<html>
<body>
<a href="http://www.example.com">Example</a>
<a href="http://www.stackoverflow.com">SO</a>
</body>
</html>
The xpath query /html/body//a/@href (or simply //a/@href ) will return: xpath 查询/html/body//a/@href （或简单地//a/@href ）将返回：
http://www.example.com
http://www.stackoverflow.com
To select a specific instance use /html/body//a[N]/@href ,要选择特定实例，请使用/html/body//a[N]/@href ，
$ /html/body//a[2]/@href
http://www.stackoverflow.com
To test for strings contained in the attribute and return the attribute itself place the check on the tag not on the attribute:要测试属性中包含的字符串并返回属性本身，请检查标签而不是属性：
$ /html/body//a[contains(@href,'example')]/@href
http://www.example.com
Mixing the two:两者混合：
$ /html/body//a[contains(@href,'com')][2]/@href
http://www.stackoverflow.com
解决方案2
1 2020-01-05 04:02:38
The answer shared by @mockinterface is correct. @mockinterface 分享的答案是正确的。 Although I would like to add my 2 cents to it.虽然我想加上我的 2 美分。
If someone is using frameworks like scrapy the you will have to use /html/body//a[contains(@href,'com')][2]/@href along with get() like this:如果有人使用像scrapy的框架，你将不得不像这样使用/html/body//a[contains(@href,'com')][2]/@href和 get() ：
response.xpath('//a[contains(@href,'com')][2]/@href').get()
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