20 Days of Python — Mini Projects

A daily-practice repo: small, self-contained Python projects, from core language fundamentals to basic data work. Each day lives in its own folder with its own code, README, and (where it makes sense) tests.

Goal

Build hands-on, practical experience with Python — one small project at a time — moving from console programs and OOP fundamentals (core-python/) into working with real data (data-basics/).

Repo structure

mini-projects/
├── README.md
├── requirements.txt
│
├── core-python/
│   ├── 01-guess-number-game/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 02-calculator-pro/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 03-todo-app/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 04-rock-paper-scissors/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 05-treasure-island/
│   │   ├── main.py
│   │   └── README.md
│   ├── 06-password-generator/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 07-hangman-game/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 08-quiz-app/
│   │   ├── main.py
│   │   ├── questions.json
│   │   ├── test_main.py
│   │   └── README.md
│   ├── 09-banking-system/
│   │   ├── main.py
│   │   ├── test_main.py
│   │   └── README.md
│   └── 10-refactor-week/
│       ├── utils/
│       │   ├── __init__.py
│       │   └── validators.py
│       ├── test_validators.py
│       └── README.md
│
└── data-basics/          # Days 11-20 (in progress)

Design conventions used across the repo

• Every project is written as one or more classes — game/business logic separated from CLI or GUI code — instead of one flat script.
• Public methods use type hints and short docstrings.
• Anywhere the original day used a bare except:, it was replaced with a specific exception (ValueError, KeyError, a custom exception, etc.).
• Projects that don't depend on input()/GUI event loops have a test_main.py written with pytest.
• JSON is used for lightweight persistence (history, tasks, accounts) instead of anything database-related, since that's out of scope for Days 1-10.

How to run any project

cd core-python/01-guess-number-game
python main.py

How to run tests

pip install -r requirements.txt
cd core-python/01-guess-number-game   # or any other day with tests
pytest