I'm trying to create a login system using Flask and HTTP Basic Auth. My question is, is it my responsibility to provide user information from databases, or does basicauth create and access those databases for me? If it doesn't, what can I use to do that?
Werkzeug can decode the Basic Authorization header for you, into the username and password. The rest is up to you to see what you want to do with that information.
The request.authorization attribute returns a Authorization object. For basic authentication headers, only username and password are set.
A project like Flask-Login can help you manage more complex logins with Basic Authorization, and tie that in with a user model you provide. That model can be stored in a database or anything else you so desire.
And you can look at Flask-Security for a more fully integrated security package that uses Flask-Login and other packages to provide Basic Authentication and session based logins.