This repository has all the base files ready for deploying a Heroku application, including a simple database model managed with flask-sqlalchemy.
$ git clone https://github.com/yuvadm/heroku-python-skeleton.git
$ cd heroku-python-skeleton
$ heroku create
$ git push heroku master
$ heroku addons:create heroku-postgresql:hobby-dev
$ heroku run python
and in the Python REPL:
>>> from app import db
>>> db.create_all()
For a detailed introduction see http://blog.y3xz.com/blog/2012/08/16/flask-and-postgresql-on-heroku/.