A session factory that stores data serialized in memcache.
To use memcache sessions, pass this class as the factory keyword to webapp2_extras.sessions.SessionStore.get_session():
from webapp2_extras import sessions_memcache
# [...]
session = self.session_store.get_session(
name='mc_session',
factory=sessions_memcache.MemcacheSessionFactory)
See in webapp2_extras.sessions.SessionStore() an example of how to make sessions available in a webapp2.RequestHandler.