I would try with:
.//a[text()='Example']
using xpath() method:
tree.xpath(".//a[text()='Example']")[0].tag
If case you would like to use iterfind(), findall(), find(), findtext(), keep in mind that advanced features like value comparison and functions are not available in ElementPath.
lxml.etree supports the simple path syntax of the find, findall and findtext methods on ElementTree and Element, as known from the original ElementTree library (ElementPath). As an lxml specific extension, these classes also provide an xpath() method that supports expressions in the complete XPath syntax, as well as custom extension functions.