flask_project_structure

My take on writing flask APIs and micro-services. This repo is a boilerplate for writing flask restful APIs. Includes:

1. A proper way to separate configs in Production, Development and Testing
2. SQL Alchemy build-in, with CRUD operations
3. Email service configured
4. Password and Token Authentication handled using Argon2 and PyJWT
5. Pymongo functions written to do basic CRUD operations

i.e. most of the boring stuff done in one place!

To run for the first time

Step 0: Get folder

Clone: git clone <link>

Goto dir: cd <dir> or maybe inside project workspaces if you want individual venvs for each project!

Step 1: Create virtual environment

python -m virtual venv

Step 2: Start virtual environment

Windows: venv\Scripts\activate

Linux: source\bin\activate

Step 3: Install Requirements

pip install -r requirements.txt

Run the flask app

Note: Must be inside the folder where run.py is visible!

Set env

Windows: set FLASK_APP=run.py (Powershell will not work out-of-the-box. Use cmd!)

Linux: export FLASK_APP=run.py

Run

flask run

Optional parameters: [Use flask run <params1> <params2> <params3>]

• -h 0.0.0.0 : sets host to 0.0.0.0
• -p 9876 : sets port to 9876 (use any valid port)
• --with-threads : use multi-threading
• --help : more useful options

Install DB Requirements

• For sql:

  • MySQl: mysql
  • Postgres: psycopg2

• For Mongo: pymongo

And then update requirements.txt

Update requirements.txt if new packages are installed

pip freeze > requirements.txt

Note: NEVER EVER update the requirements.txt manually!

Understating the Project structure

A few Topics that should be cleared out before hand

This things are sometimes called advanced topics in Python/Flask/Web-dev in general, so people usually don't include them in beginner courses and tutorials. But going thought these helped me understand a lot!

(Btw, if you are new to python, heres a book: Python for you and me

Modules, Packages and Imports in Python

• Absolute vs Relative Imports in Python Realpython article
• Python Modules and Packages Realpython article

Password hashing and Argon 2

Argon2 is a password hashing algorithm. I used argon2-cffi - a python library that implements that algorithm with a simple way to use it!

• Why Hash Passwords and technologies involved! Auth0 Blog
• Basic Knowledge: argon2-cffi docs
• Detailed Algorithm here

Authentication and JWT Tokens

• Most Used Rest-api Authentication Types and where to use what! Restcase article
• JWT Introduction: JWT.io
• JWT Detail Read: Auth0 docs
• PyJWT docs

Python and concurrency/parallelism

Python is different from most other languages, we all agree, but when it comes to concurrency, well, let's say its most different!

Although this repo has not implemented any async methods, since you learned all those above topics, why leave this!

• Thread vs Process: GeeksForGeeks
• Python's GIL: Realpython article and/or Python wiki
• Thread vs Process in python: medium @bfortuner's blog
• Also look in python threading module and multiprocessing module

A few general things

• Functions solving 1 problem are grouped in a File.

• Files solving similar problem are in a folder.

• project_root is a placeholder. It can be safely renamed to anything. To achieve this flexibility, most of the code inside uses relative imports. Therefore Do Not move folders around blindly.

• Once copied for your project, make sure to edit this README.md. Always write a detailed README, it is useful for newcomers to the project!

more doc will be added...