You can do the "1 file thing" with either. It's enforced in Bottle but not in Flask. I've used both and would recommend going with a Flask(web-framework)/SQLAlchemy(database or part that "grabs data") combo that sends JSON to a javascript chart/graph library.
You should be able to find a number of Flask/Backbone demos on github. Checking out a few of those would be a good place to start, even though you'll probably be scrapping backbone and just using a javascript charting library instead.
You should be able to find a number of Flask/Backbone demos on github. Checking out a few of those would be a good place to start, even though you'll probably be scrapping backbone and just using a javascript charting library instead.