Flask-Auth is a flask extension that offers database-agnostic (but still fairly plug-and-play) role-based user authentication. Sounds impressive, right?

• Set of functions to assist in user session management (logging in and out, getting the current user, expiring sessions, encrypting passwords, etc).
• Base user class AuthUser that can be used with most ORM's.
• Plug-and-play model for Google App Engine (and a working example for SQLAlchemy and MongoAlchemy).
• Straightforward permission model to differentiate access rights between (groups of) users.

Documentation can be found on PyPI.