python - Select and modify xpath nodes after specific text

Question

I use this code to get all names:

def parse_authors(self, root): 
    author_nodes = root.xpath('//a[@class="booklink"][contains(@href,"/author/")]/text()')
    if author_nodes:
        return [unicode(author) for author in author_nodes]

But i want if there are any translators to add "(translation)" next to their names:

example:translator1(translation)

Answer 1

You can use that translation: text node to distinguish authors from translators - authors are preceding siblings of the "translation:" text node, translators - following siblings.

Authors:

//text()[contains(., 'translation:')]/preceding-sibling::a[@class='booklink' and contains(@href, '/author/')]/text()

Translators:

//text()[contains(., 'translation:')]/following-sibling::a[@class='booklink' and contains(@href, '/author/')]/text()

Working sample code:

from lxml.html import fromstring

data = """
<td>
    <a class="booklink" href="/author/43710/Author 1">Author 1</a>
    ,
     <a class="booklink" href="/author/46907/Author 2">Author 2</a>
     <br>
     translation:
     <a class="booklink" href="/author/47669/translator 1">Translator 1</a>
     ,
     <a class="booklink" href="/author/9382/translator 2">Translator 2</a>
</td>"""

root = fromstring(data)

authors = root.xpath("//text()[contains(., 'translation:')]/preceding-sibling::a[@class='booklink' and contains(@href, '/author/')]/text()")
translators = root.xpath("//text()[contains(., 'translation:')]/following-sibling::a[@class='booklink' and contains(@href, '/author/')]/text()")

print(authors)
print(translators)

Prints:

['Author 1', 'Author 2']
['Translator 1', 'Translator 2']