Is there an elegant way to count tag elements in a xml file using lxml in python?

Question

I could read the content of the xml file to a string and use string operations to achieve this, but I guess there is a more elegant way to do this. Since I did not find a clue in the docus, I am sking here:

Given an xml (see below) file, how do you count xml tags, like count of author-tags in the example bewlow the most elegant way? We assume, that each author appears exactly once.

<root>
    <author>Tim</author>
    <author>Eva</author>
    <author>Martin</author>
    etc.
</root>

This xml file is trivial, but it is possible, that the authors are not always listed one after another, there may be other tags between them.

Answer 1

If you want to count all author tags:

import lxml.etree
doc = lxml.etree.parse(xml)
count = doc.xpath('count(//author)')