I'm trying to get some elements from a page. Unfortunately it results with an empty list. The pretty-printed tree includes this element:
<html:a title="..." href="..." id="..." class="topic_title">...</html:a>
However when I do this on the same tree:
page.xpath('''.//a[@class="topic_title"]''')
I get an empty list. The tree was created with html5lib / lxml treebuilder.
It seems as if you are dealing with XHTML, so you could register the namespace html before evaluating the XPath expression:
page.xpath('''.//html:a[@class="topic_title"]''',
namespaces={'html': 'http://www.w3.org/1999/xhtml'})
See also Namespaces and Prefixes:
If your XPath expression uses namespace prefixes, you must define them in a prefix mapping. To this end, pass a dictionary to the namespaces keyword argument that maps the namespace prefixes used in the XPath expression to namespace URIs.
