lxmlresponse.py

import requests
import requests.models
import lxml.html
import cached_property

class LxmlResponse(requests.models.Response):
    @classmethod
    def use_in_session(cls, session=None):
        if not session:
            session = requests.Session()
        session.hooks['response'].append(cls._hook_response)
        return session 

    @classmethod
    def _hook_response(cls, response, *args, **kwargs):
        response.__class__ = cls
        return response

    @cached_property.cached_property
    def document(self):
        return lxml.html.fromstring(self.content, base_url=self.url)

    def find(self, selector):
        for result in self.find_all(selector):
            return result
        return None

    def find_all(self, selector):
        return self.document.cssselect(selector)

session = LxmlResponse.use_in_session()
print(session.get('http://example.com').find('a').get('href'))