I have tried this
url = 'http://test.ir/'
content = s.get(url).content
tree = html.fromstring(content)
print [e.text_content() for e in tree.xpath('//div[@class="grouptext"]/text()[not(self:div)]')]
As you can see in the picture I want the selected part:

When I use
print [e.text_content() for e in tree.xpath('//div[@class="grouptext"]')]
The result shows me the selected part and the content of <div class="grouptext"> as well.