Turtle Challenges

Solutions to the five turtle graphics challenges of day 18 of Udemy's 100 Days of Code: The Complete Python Pro Bootcamp: draw a square, draw a dashed line, draw different shapes, generate a random walk and draw a spirograph. The code is small, readable and tested, keeps the function names of the assignment, and needs nothing beyond the Python standard library to run.

Requirements

• Python 3.13 or later, with Tk (tkinter), which the turtle module draws with. The Windows and macOS installers include it; on Debian it is the python3-tk package.
• git, to clone the repository.
• No runtime dependencies. The development tools (pytest, ruff, mypy) are installed by the dev extra in the steps below.
• Doxygen, only to build the source documentation.

Set up

The same four steps on every system: clone, create a local virtual environment named .venv, upgrade pip inside it, and install the project in editable mode with its development tools. The virtual environment keeps the project's packages apart from every other Python project on the machine; do not install them system-wide.

The Windows PowerShell steps are the ones the author has run. The Debian and macOS steps use the same Python commands but have not been verified.

Windows PowerShell

git clone https://github.com/Tirsvad-Udemy-100-days-of-code/018-turtle.git
cd 018-turtle
py -3.13 -m venv .venv
.\.venv\Scripts\Activate.ps1
python -m pip install --upgrade pip
python -m pip install -e ".[dev]"

If PowerShell refuses to run Activate.ps1 because scripts are disabled, allow scripts for this window only and activate again:

Set-ExecutionPolicy -Scope Process -ExecutionPolicy RemoteSigned
.\.venv\Scripts\Activate.ps1

The prompt starts with (.venv) while the environment is active. Type deactivate to leave it. Activate it again in every new terminal before you run the project.

Linux Debian

sudo apt update
sudo apt install --yes git python3 python3-venv python3-tk
git clone https://github.com/Tirsvad-Udemy-100-days-of-code/018-turtle.git
cd 018-turtle
python3 -m venv .venv
source .venv/bin/activate
python -m pip install --upgrade pip
python -m pip install -e ".[dev]"

Check that python3 --version prints 3.13 or later. If the package manager offers an older Python, install 3.13 another way (for example with pyenv) before creating the environment.

MacOS

brew install git python@3.13 python-tk@3.13
git clone https://github.com/Tirsvad-Udemy-100-days-of-code/018-turtle.git
cd 018-turtle
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, run one challenge by name. A window opens, the turtle draws, and the window closes when you click it.

turtle-challenges square
python -m turtle_challenges dashed-line

Challenge	Command	Function
1. Draw a square	turtle-challenges square	draw_square
2. Draw a dashed line	turtle-challenges dashed-line	draw_dashed_line
3. Draw different shapes	turtle-challenges shapes	draw_shape, draw_shapes, random_color

Challenges 4 and 5 are added by milestone 004.

turtle-challenges --help lists the challenges. If the command prints that the turtle module needs Tk, install Tk as described under Requirements.

To use the functions in your own code, create a window and a turtle, then pass the turtle as the first argument. The assignment's functions use one global turtle; here the turtle is a parameter, which is what lets the tests run without a window:

from turtle_challenges import draw_square
from turtle_challenges.window import create_pen, create_window

window = create_window()
tim = create_pen()
draw_square(tim)
window.exitonclick()

Run the tests

The tests never open a window: they pass a recording fake in place of the turtle and check the moves it recorded. With the virtual environment active:

python -m pytest

The same checks as in continuous integration:

ruff check .
ruff format --check .
mypy

Continuous integration

.github/workflows/ci.yml runs on every push to main and on every pull request. It is read by both GitHub Actions and Gitea Actions. It sets up Python 3.13, upgrades pip, installs the project with its development tools, then runs ruff (lint and format check), mypy, pytest and the Doxygen build. No step opens a turtle window.

Build the source documentation

The source carries Doxygen comments, and the Doxyfile builds them, with this README as the main page. Install Doxygen first (winget install DimitriVanHeesch.Doxygen on Windows, sudo apt install doxygen on Debian, brew install doxygen on macOS), then run from the repository root:

doxygen Doxyfile

Open build/html/index.html in a browser. Any Doxygen warning fails the build, so every module, function and constant has to stay documented.

Project layout

.
├── .github/workflows/ci.yml   continuous integration
├── docs/                      project documents: business case, plan, milestones
├── src/turtle_challenges/     the package
│   ├── constants.py           every constant of the project
│   ├── pen.py                 the Pen and Window protocols the challenges use
│   ├── window.py              opens the turtle window and creates the turtle
│   ├── colors.py              random_color and random_palette_color
│   ├── square.py              challenge 1: draw_square
│   ├── dashed_line.py         challenge 2: draw_dashed_line
│   ├── shapes.py              challenge 3: draw_shape, draw_shapes
│   └── cli.py                 the turtle-challenges command
├── tests/                     pytest tests and the recording fake pen
├── Doxyfile                   Doxygen configuration
├── pyproject.toml             project, tool and dependency configuration
└── LICENSE

The framework/ folder is a git submodule with the quality framework that the documents in docs/ follow. The project does not need it to run, test or build.

License

GNU Affero General Public License version 3. See the LICENSE file.