title: Need a python authentication / authorization framework
body: <p>I'm writing a web application that requires authentication / authorization. That is, this web app will allow users to log into the site and gain access to material not accessible to anonymous users. Unfortunately, Flask does not come with a built in authentication / authorization system. Experts highly discourage rolling out a custom system, so I don't want to do this. Is there a good, full-fledged authentication / authorization framework that I can use for my application?</p>