python - 我如何在 python lxml、XPath 中使用正则表达式

Question

我正在尝试:

for element in root.xpath('//a[@id="hypProduct_[0-9]+"]'):

如何在 xpath 元素选择器 (lxml) 中使用 [0-9]+？文档状态:

By default, XPath supports regular expressions in the EXSLT namespace:

>>> regexpNS = "http://exslt.org/regular-expressions"
>>> find = etree.XPath("//*[re:test(., '^abc$', 'i')]",
...                    namespaces={'re':regexpNS})

>>> root = etree.XML("<root><a>aB</a><b>aBc</b></root>")
>>> print(find(root)[0].text)
aBc

You can disable this with the boolean keyword argument regexp which defaults to True.

我没有遵循 :test 的内容。有人可以在文档的上下文中对此进行解释。

Answer 1

在您的情况下，表达式将是:

//a[re:test(@id, "^hypProduct_[0-9]+$")]

演示:

>>> from lxml.html import fromstring
>>> 
>>> data = '<a id="hypProduct_10">link1</a>'
>>> tree = fromstring(data)
>>> tree.xpath('//a[re:test(@id, "^hypProduct_[0-9]+$")]', namespaces={'re': "http://exslt.org/regular-expressions"})[0].attrib["id"]
'hypProduct_10'