[Python-Dev] Security capabilities in Python

I would like to experiment with security based on Python references as security capabilities. Unfortunatly, there are several problems that make Python references invalid as capabilities: * There is no way to create secure proxies because there are no private attributes. * Lots of Python objects are reachable unnecessarily breaking the principle of least privelege (i.e: object.__subclasses__() etc.) I was wondering if any such effort has already begun or if there are other considerations making Python unusable as a capability platform? (Please cc the reply to my email)