This repository has a structure of how a large flask application should look like.
It's a sample code base for ideas discussed over https://www.digitalocean.com/community/tutorials/how-to-structure-large-flask-applications
$ virtualenv env
$ . env/bin/activate
$ pip install -r requirements.txt
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$ python manager.py test
$ python manager.py upgrade
$ python manager.py seed
$ python manager.py runserver
localhost:5000/users
localhost:5000/users/1