FLASK - API | ORM with SQLAlchemy

[Work in progress...]

Table of contents

• General info
• Technologies
• Setup
• Flask
• Project Structure
• Models
• Schemas
• Inspiration

🗣️ About

Simple Python Flask CRUD Application based on Flask-SQLAlchemy. In this application we are connecting a database where we add, retrieve, update and delete users. The app also handles users authentication through json web tokens.

Technologies

Project is created with:

• FLASK
  • Flask-SQLAalchemy: Database ORM
  • Flask-Migrate: Database updates
  • Flask_Bcrypt: Encrypt passwords
  • Flask-Marshmallow: Helps with serializing and deserializing objects. Transform our SQLAlchemy objects into readable JSON data and helps to validate users data inputs.

Setup

To run this project clone the project and:

cd ../<project-name>
virtualenv env --python=python3.9 # Recomended
source env/bin/activate # Recomended
pip install -r requirements.txt
python run.py

Project Structure

DATABASE SET UP - Flask-migrate

Flask_migrate

Flask extension that is used to migrate sqlalchemy based database models. When adding columns, migrate will compare the current version and the new version and create a script to migrate from one to the other. Once you have data it becames very usefull extension.

Commands

python migrate.py db init # First time to create unexisting tables

python migrate.py db migrate

python migrate.py db upgrade

Flask "Application Factory" Pattern

benefits:

• 1. Stop/avoid circular import;
• 2. Better and easier setup, for example, test, different environments;
• 3. More organized and readable project.

Functional Based Structure

There are many ways to setup your project folder structure. One is by its function. For instance:

project/
  __init__.py
  models/
    __init__.py
    base.py
    users.py
    posts.py
    ...
  routes/
    __init__.py
    home.py
    account.py
    dashboard.py
    ...
  templates/
    base.html
    post.html
    ...
  services/
    __init__.py
    google.py
    mail.py
    ...

All things are grouped by its function. If it hehaves as a model, put it in models folder; if it behaves as a route, put it in routes folder. Build a create_app factory in project/init.py, and init_app of everything:

Models

Schemas