python-ddd-architecture-for-php-devs

Intro

The project was made for PHP (Symfony) developers like me, who were curious if it's possible to make something similar using Python and its libraries.

I feel like there are a lot of programmers who wanted to try Python. But they were back to PHP after encountering Django.

TODO

• Design Level Event Storming diagrams
• Make an aggregate, figure out some domain context and implement
• Command-Handler, though queues as well - like Messenger in Symfony
• Implementation of Domain Events https://udidahan.com/2009/06/14/domain-events-salvation/
• Implementation of a read model (CQRS)
• Show how to write tests (pytest)
• Static analysis tools (mypy)
• ...
• Invite to cooperation :)

Domain description and requirements

The system allows clients to subscribe to the gym (60EUR per month).

Requirements:

• registration new clients
• active clients will be billed monthly automatically
  • billing is processed every first day of the month
• the system can apply bonuses
  • percents or amounts
  • if the client has a birthday in the current month, the customer is entitled to a percentage discount (50%)
  • for new clients will have amount discount (20EUR)
  • if the client is employed in the gym, is entitled to a free subscription (100%)

Examples:

• John has a birthday in February, he should pay 50% less
• Charlotte is new at the gym, her first payment will be 20EUR less
• Emma works at the gym, and have a subscription, have a free subscription
• Emma as a gym employee also has to:
  • generate monthly reports
  • filter users by name, surname, and email, and check if the subscription is active

Stack

• Python 3.10
• FastAPI
• PostgreSQL

Setup

1. Install dependencies:

$ poetry install

If you don't have poetry yet: https://python-poetry.org/docs/

Running app locally

1. Run docker-compose up -d
2. Go to app.py and run the app

Tests

$ poetry run pytest

or

$ make tests