024-snake/README.md

Snake Game (Day 24)

The classic Snake game, built with Python's turtle module. It is the day-24 assignment of Udemy's 100 Days of Code: The Complete Python Pro Bootcamp. Day 24 teaches the local file system and reading and writing files with open and the with keyword, and applies them to the snake game: the scoreboard shows a high score next to the score, the game goes on after a collision instead of ending, and the high score is kept in the file data.txt, so it is still there the next time the game is started.

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

This repository continues 021-snake-game and starts from its finished game; docs/project-plan.md tells how the work is split into milestones.

Status: finished. The game of day 21 is adopted and follows the day-24 lectures: continuous play, a high score next to the score, and the high score kept in the file data.txt. A short description of the game in English, Danish and Bahasa Melayu is on the wiki of the repository (the pages are in wiki/).

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/024-snake.git
cd 024-snake

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

It opens a black 600 by 600 window titled "My Snake Game". The snake of three squares starts in the middle and moves to the right by itself, 20 pixels every 0.1 seconds. Its body is light green and its head is dark green with a mouth.

Key	Effect
Up, Down, Left, Right	Turn the snake

The snake never turns straight back onto itself: the arrow key opposite to the way it is going is ignored.

A small blue circle, the food, appears at a random place. When the head comes closer to it than 15 pixels the snake eats it: the food moves to a new random place, the snake grows by one segment, and the score at the top of the window goes up by 1.

The scoreboard at the top of the window reads Score: 0 High Score: 0. The score counts the foods eaten since the last reset; the high score is the best score so far.

The game does not end. When the head passes the wall (more than 280 pixels from the centre on any side) or touches the tail, the old snake is sent off the screen, a new snake of three segments appears in the middle, the score goes back to 0, and the high score is raised if the score was higher. Close the window with its close button when you have had enough.

The high score file

The high score is kept as text in the file data.txt, in the folder you start the game from (python -m snake_game). The game reads it when it starts and writes it again each time a new high score is reached, so the high score is still there the next time you play. The file is created holding 0 the first time, and a file that is empty or does not hold a whole number is read as 0. To start from zero again, close the game and delete data.txt. The file is your own state and is ignored by git. Start the game from another folder and it uses the data.txt of that folder.

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 a 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
│   ├── __main__.py            starts the game: python -m snake_game
│   ├── constants.py           every constant of the game
│   ├── food.py                the Food class (inherits from Turtle)
│   ├── high_score_file.py     read_high_score and write_high_score (data.txt)
│   ├── main.py                screen set-up and the main flow
│   ├── scoreboard.py          the Scoreboard class (inherits from Turtle)
│   └── snake.py               the Snake class
├── tests/                     pytest tests (fakes.py holds the fake turtle and screen;
│                              conftest.py runs every test in a temporary folder)
├── wiki/                      wiki pages in English, Danish and Bahasa Melayu
├── Doxyfile                   source documentation settings
├── LICENSE
├── pyproject.toml             project configuration
└── README.md

License

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