tarball.tar.gz

POSTGRES_USER

POSTGRES_PASSWORD

POSTGRES_HOSTNAME

APPLICATION_DB

POSTGRES_PORT

POSTGRES_DB

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

The previous chapter discussed how to integrate a real external system with the core of clean architecture. Unfortunately, we also had to introduce a lot of code to manage the integration tests and move forward to a proper setup. 

In this chapter, we’ll employ what we’ve learned so far to show only the part of the code that’s connected with the external system. Swapping the database from PostgreSQL to MongoDB is the perfect way to show how flexible clean architecture is and how easy it is to introduce different approaches like a non-relational database instead of a relational one.


Let’s have a brief introduction to using MongoDB as a repository.

Overview of MongoDB

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

Overview of MongoDB