FWIW, a couple of years ago I wrote an implementation of a multi-index container with an ORM-ish interface (http://norman.readthedocs.org/en/latest/), more for my own amusement than any practical purposes. However, I found that in my work the applications were actually rather limited and generally better served by sqlalchemy + appropriate db, or pandas (depending on use case). I haven't touched the code in quite a while and there may be some bugs that I never discovered, but it might still be of some use.
David