Question

How do I escape the forward slash character in an xpath query? My tags contain a url, so I need to be able to do this. I am using lxml in python.

Alternatively, is it possible for xpath to query a substring of the path? Examples are below:

xml="""
<entry xmlns="http://www.w3.org/2005/Atom" xmlns:gsa="http://schemas.google.com/gsa/2007">
  <gsa:content name="reportName">bbb</gsa:content>
  <gsa:content name="collectionName">default_collection</gsa:content>
  <gsa:content name="reportDate">date_3_25_2009</gsa:content>
 </entry>
"""

When I run the following:

tree=fromstring(xml)
for elt in tree.xpath('//*'):
    elt.tag

It returns:

'{http://www.w3.org/2005/Atom}entry'
'{http://schemas.google.com/gsa/2007}content'
'{http://schemas.google.com/gsa/2007}content'
'{http://schemas.google.com/gsa/2007}content'

Running tree.xpath('/entry') returns an empty list.

I need to be able to either query for ‘{http://www.w3.org/2005/Atom}entry’ as the tag, or query for ‘entry’ anywhere in the tag.

Answer 1

Look into namespace prefixes^[docs].

If you want an element that’s in the http://schemas.google.com/gsa/2007 namespace you need to search for it like so:

import lxml.etree as et

xml="""
<entry xmlns="http://www.w3.org/2005/Atom" xmlns:gsa="http://schemas.google.com/gsa/2007">
  <gsa:content name="reportName">bbb</gsa:content>
  <gsa:content name="collectionName">default_collection</gsa:content>
  <gsa:content name="reportDate">date_3_25_2009</gsa:content>
 </entry>
"""

NS = {'rootns': 'http://www.w3.org/2005/Atom',
      'gsa': 'http://schemas.google.com/gsa/2007'}

tree = et.fromstring(xml)

for el in tree.xpath('//gsa:content', namespaces=NS):
    print el.attrib['name']

print len(tree.xpath('//rootns:entry', namespaces=NS))