I'm currently supporting a Python web app with increasingly complicated user/role/permission management requirements. Currently, we are rolling our own user, groups, permissions, etc. code and supporting database.
I'd like to find something like ASP.NET membership that can help manage user authentication and authorization, rather than risk security issues in continuing to create an increasingly complicated custom solution. Are there any similar projects out there worth taking a look at?
If you are looking for off site user authentication you might want to consider openid. People have added openid support to cherrypy.
If you are looking for more user management type code. I guess it depends on exactally what you are doing but others have done user management before, why not leverage off them. Skeletonz is a CMS written on top of cherrypy. If you are not wed to cherrypy you might also want to consider Pinax. It's built on Django with the idea of reusing work others have done so you don't have to do it again.