Snake Game (Day 21)

The classic Snake game, built object-oriented with Python's turtle module. It is the day-21 assignment of Udemy's 100 Days of Code: The Complete Python Pro Bootcamp: a snake moves across a black 600 by 600 screen by itself and is steered with the arrow keys; it eats food, grows, and a score is shown at the top; the game is over when the head passes the wall or touches its own tail. Day 21 teaches class inheritance (Food and Scoreboard inherit from Turtle) and slicing (the tail is segments[1:]).

The game has no runtime dependencies. The code keeps the names of the lectures (Snake, create_snake, move, up, down, left, right, segments, head, game_is_on, Food, Scoreboard, refresh, extend, increase_score, game_over) so that you can compare it with your own solution.

This repository continues 020-snake-game and starts from its finished game; docs/project-plan.md tells how the work is split.

Status: the project foundation is in place (environment, constants, tests, source documentation, continuous integration). The game itself, python -m snake_game, is added by the next milestone, MIL-002.

Requirements

• Python 3.13 or newer, with tkinter (the turtle module needs it).
• git, to clone the repository.
• Optional: Doxygen to build the source documentation.
• No runtime dependencies. The development tools (pytest, ruff, mypy) are installed into the virtual environment by the dev extra.

Set up

Clone the repository, then create a local virtual environment .venv in its root, upgrade pip and install the project with its development tools. The .venv folder is ignored by git.

git clone https://git.tirsystem.com/Tirsvad-Udemy-100-days-of-code/021-snake-game.git
cd 021-snake-game

Windows powershell

python -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
python -m pip install -e ".[dev]"

If PowerShell refuses to run the activation script, allow scripts for this window only with Set-ExecutionPolicy -Scope Process -ExecutionPolicy RemoteSigned and activate again. Python from python.org includes tkinter.

Linux debian

Debian 13 or newer ships Python 3.13. On older releases install Python 3.13 separately.

sudo apt install python3 python3-venv python3-tk
python3 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -e ".[dev]"

MacOS

brew install python@3.13 python-tk@3.13
python3.13 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -e ".[dev]"

Run

With the virtual environment active:

python -m snake_game

The game is not in the repository yet: python -m snake_game works once MIL-002 is merged, and this section is then completed with the keys, the food, the score and the game-over rules.

Run the tests

The tests need no display: they use fakes instead of real turtles.

pytest

The same checks that continuous integration runs:

python -m pytest
python -m ruff check src tests
python -m ruff format --check src tests
python -m mypy

Continuous integration

.gitea/workflows/ci.yml runs on Gitea Actions on every push and on every pull request. It sets up Python 3.13, upgrades pip, installs .[dev], then runs pytest, ruff (lint and format check) and mypy. It does not build the source documentation: run doxygen Doxyfile yourself, as the next section shows. No step opens a turtle window.

The workflow lives in .gitea/workflows and not in .github/workflows, so GitHub does not run it and pushing to the GitHub mirror needs no workflow permission.

Build the source documentation

The source is documented with Doxygen comments and the Doxyfile in the root. Install Doxygen (winget install DimitriVanHeesch.Doxygen on Windows, sudo apt install doxygen on Debian, brew install doxygen on macOS), then:

doxygen Doxyfile

The HTML is written to build/doxygen/index.html. A warning fails the build.

Project layout

.
├── .gitea/workflows/ci.yml    continuous integration (Gitea Actions)
├── docs/                      business case, plan, milestones, reviews
├── src/snake_game/            the game
│   ├── __init__.py
│   └── constants.py           every constant of the game
├── tests/                     pytest tests
│   └── test_constants.py
├── Doxyfile                   source documentation settings
├── LICENSE
├── pyproject.toml             project configuration
└── README.md

The game modules (snake.py, food.py, scoreboard.py, main.py, __main__.py) and their tests are added by MIL-002.

License

GNU Affero General Public License v3.0 only. See LICENSE.