如何使用LXML以递归方式查找XML标记？

Question

<?xml version="1.0" ?>
<data>
    <test >
        <f1 />
    </test >
    <test2 >
        <test3>
         <f1 />
        </test3>
    </test2>
    <f1 />
</data>

Using lxml is it possible to find recursively for tag " f1 "? I tried findall method but it works only for immediate children.

I think I should go for BeautifulSoup for this !!!

Answer 1

You can use XPath to search recursively:

>>> from lxml import etree
>>> q = etree.fromstring('<xml><hello>a</hello><x><hello>b</hello></x></xml>')
>>> q.findall('hello')     # Tag name, first level only.
[<Element hello at 414a7c8>]
>>> q.findall('.//hello')  # XPath, recursive.
[<Element hello at 414a7c8>, <Element hello at 414a818>]

Answer 2

iterfind() iterates over all Elements that match the path expression

findall() returns a list of matching Elements

find() efficiently returns only the first match

findtext() returns the .text content of the first match

Illustrative Examples:

>>> root = etree.XML("<root><a x='123'>aText<b/><c/><b/></a></root>")
#Find a child of an Element:
>>> print(root.find("b"))
None
>>> print(root.find("a").tag)
a
#Find an Element anywhere in the tree:
>>> print(root.find(".//b").tag)
b
>>> [ b.tag for b in root.iterfind(".//b") ]
['b', 'b']
#Find Elements with a certain attribute:
>>> print(root.findall(".//a[@x]")[0].tag)
a
>>> print(root.findall(".//a[@y]"))
[]

Reference: http://lxml.de/tutorial.html#elementpath

(This answer is relevant selective selection from the content at this link)