Common folder/file structure in Flask app

Question

I have just created a flask application and so far I have a router for my "Hello world!" template.

I would like to add a little (a lot) more functionality, but I wonder how I should structure the app directory.

What's the most common way of structuring a Flask app? For instance, should I create a routes.py for all my routes? Where does the SQLAlchemy stuff go? Should models be in models.py?

Answer 1

You should check out the Larger Applications page in the Patterns section of the Flask docs: http://flask.pocoo.org/docs/patterns/packages/. It seems to be the model that most people follow when their application calls for a package instead of a module.

I believe views.py is what you are calling routes.py. After that, models would go in models.py, forms would go in forms.py, etc.

Answer 2

An example of a FlaskApp directory:

    /yourapp  
        /run.py  
        /config.py  
        /app  
            /__init__.py
            /views.py  
            /models.py  
            /static/  
                /main.css
            /templates/  
                /base.html  
        /requirements.txt  
        /yourappenv

run.py - contains the actual python code that will import the app and start the development server.
config.py - stores configurations for your app.
__init__.py - initializes your application creating a Flask app instance.
views.py - this is where routes are defined.
models.py - this is where you define models for your application.
static - contains static files i.e. CSS, Javascript, images
templates - this is where you store your html templates i.e. index.html, layout.html
requirements.txt - this is where you store your package dependancies, you can use pip
yourappenv - your virtual environment for development

Answer 3

I would say if you split the application use divisional rather than functional structure. I advocate this because you are more likely to work on 1 of these divisional components at any one time.

This type of structure lends itself well on marketplace or SaaS apps where different user groups use a different type of views. API only flask app I might use functional splitting.

Here are examples from Flask Blueprints. Blueprints are essentially documented advice how to split Flask application for more manageable pieces. More on this at : http://exploreflask.com/en/latest/blueprints.html

Here is an example of divisional splitting. See how each feature is grouped together.

yourapp/
    __init__.py
    admin/
        __init__.py
        views.py
        static/
        templates/
    home/
        __init__.py
        views.py
        static/
        templates/
    control_panel/
        __init__.py
        views.py
        static/
        templates/
    models.py

Here is the functional example >

yourapp/
    __init__.py
    static/
    templates/
        home/
        control_panel/
        admin/
    views/
        __init__.py
        home.py
        control_panel.py
        admin.py
    models.py