Gain insights into clean architecture using Python. Delve into layered systems, design efficient applications, and integrate web components, error handling, and databases with test-driven development practices.

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Python Execution

Flask

Flask + Postgres

Python Test

Clean architecture is a software design methodology that separates the processes of an application into discrete steps instead of presenting them as “spaghetti code.” With the versatility of Python, software engineers can build performant, modular applications quickly using the Flask framework.

This course will help you build better applications using the principles of clean architecture. You’ll start with an introduction to data flow in clean systems and learn about the advantages of layered architectures. Next, you’ll learn system components and the connections between application layers. You’ll then design and build a clean system using Python by layering components in guided coding exercises. Finally, you’ll learn how to add functional components for the web, handle errors, and work with external databases using both Postgres and MongoDB. At each step, you’ll use test-driven development practices to ensure robust functionality.

Clean Architecture in Python

Thanks to the flexibility of clean architecture, providing support for multiple storage systems is a breeze. 







In this section, we’ll implement the `MongoRepo` class that provides an interface for MongoDB. We’ll follow the same testing strategy we used for PostgreSQL. We’ll have a Docker container that runs the database and Docker Compose that orchestrates the whole system.

The complex testing structure that we created in the previous chapter will help us in doing this. It will allow us to reuse some fixtures, since we now want to implement tests for a new storage system.


Let’s start defining the `tests/repository/mongodb/conftest.py` file. This file will contain `pytest` fixtures for MongoDB, mirroring the file we created for PostgreSQL.


Let’s learn about the basic requirements of MongoDB and Docker Compose configuration.

Get Started

A Day in the Life of a Clean System

Components of Clean Architecture

A Simple Coding Example

Add a Web Application

Error Management

Integration with a Real External System Postgres

Integration with a Real External System MongoDB

Run a Production-ready System

Appendix

Fixtures and Docker Compose