To be honest, I'm not terribly familiar with HasParentQuery, but I end up writing the request myself and using pyes' `search_raw` (http://packages.python.org/pyes/references/pyes.es.html#pyes.es.ES.search_raw), which takes a dictionary as described in the ES docs. If you go that route, then you'll be able to use any features your cluster supports without having to upgrade the client. For example: https://gist.github.com/4069009
--