This mini-course teaches the five SOLID object-oriented design principles through practical Python examples, real-world refactorings, and progressively challenging assignments.
Perfect for developers who want to:
- Stop writing fragile spaghetti code
- Make their codebases easy to extend, test, and maintain
By the end you’ll be able to spot SOLID violations instantly and refactor them with confidence.
Module 1: (SRP) Single Responsibility Principle - SRP.ipynb
"A class should have one, and only one, reason to change."
Module 2: (OCP) Open/Closed Principle - OCP.ipynb
"Software entities should be open for extension but closed for modification."
Module 3: (LSP) Liskov Substitution Principle - LSP.ipynb
"Subtypes must be substitutable for their base types without breaking the program breaking."
Module 4: (ISP) Interface Segregation Principle
"Clients should not be forced to depend on interfaces they do not use."
Module 5: (DIP) Dependency Inversion Principle
"Depend on abstractions, not on concretions."
All principles applied together in a complete mini e-commerce example → example.ipynb
- Clone or download the repository
- Open the notebooks in Jupyter, VS Code, Google Colab, or your favorite environment
- Follow along with the explanations
- Apply the principles to your own coding challenges
- Build the final project to cement everything
When you’ve finished all assignments and the final project, proudly add this to your LinkedIn or portfolio:
🎉 SOLID Principles Master Certificate 🎉
Awarded to: [Your Name]
Date: November 2025
"I can now look at messy code and feel physical pain."
You now have one of the highest-ROI skills in your developer toolbox.
Go forth and refactor the world.
R. Brandon Thompson
GitHub: @rb-thompson
LinkedIn: linkedin.com/in/appaltech
Originially created with Grok (xAI) on November 20, 2025.
Feel free to open issues, submit PRs, or star if this helped you level up!