quetzal

What is it?

quetzal is a Python package providing flexible models for transport planning and traffic forecasting. Quetzal is highly optimized to run fast on big cities.

Copyright

(c) SYSTRA

License

CeCILL-B

Documentation

The official documentation is hosted on https://systragroup.github.io/quetzal

Backward compatibility

In order to improve the ergonomics, the code may be re-factored and a few method calls may be re-designed. As a consequence, the backward compatibility of the library is not guaranteed. Therefore, the version of quetzal used for a project should be specified in its requirements.

Installation

https://pypi.org/project/quetzal-transport/

pip install quetzal-transport

Installation from sources

For Linux

uv

1. Install uv (if not already installed)

curl -LsSf https://astral.sh/uv/install.sh | sh

2. install dependencies (this will create a new virtualenv at .venv/ and fetch Python 3.12 if needed)

uv sync

3. activate the env

source .venv/bin/activate

4. (optional) add the env to ipykernel (to use in jupyter)

python -m ipykernel install --user --name=quetzal_env

poetry (alternative)

1. You may need to set the default (or local) python version in the project

pyenv local 3.12

2. install dependancies (this will create a new virtualenv)

poetry install

3. activate the env

poetry shell

4. (optional) add the env to ipykernel (to use in jupyter)

python -m ipykernel install --user --name=quetzal_env

For Windows

uv (recommended)

No prior installation of Python or uv is required — the batch file handles both. Open a command prompt and run the windows-install batch file

C:\users\you\path\to\quetzal> windows-install.bat

press enter to accept the default kernel name or enter a custom name

poetry (alternative)

Requires Anaconda 3 with Python 3.12. Run the poetry batch file instead:

C:\users\you\path\to\quetzal> windows-install-poetry.bat

press enter to accept the default kernel name or enter a custom name

If you are facing DLL or dependencies issues

Anaconda and Pip do not get along well, your Anaconda install may have been corrupted at some point.

• Remove your envs
• Uninstall Anaconda
• Delete your Python and Anaconda folders (users\you\Anaconda3, users\you\Appdata\Roaming\Python, ...etc)
• Install Anaconda

If you are facing SSL issues

pip config set global.trusted-host "pypi.org files.pythonhosted.org"
C:\users\you\path\to\quetzal> windows-install.bat

security warning: the host is added to pip.ini

Tests

to run unittest:

uv run python -W ignore -m unittest discover

Or with poetry:

poetry run python -W ignore -m unittest discover

Deploying

1. change the version in pyproject.toml

[project]
name = "quetzal-transport"
version = "3.1.1"

2. edit CHANGELOG.md with the changes

## [3.1.1] (2026-01-15)
## changes
* some changes

2. create a tag matching the version (starting with v)

git tag -a v3.1.1 -m 'description'

3. push the tag

git push origin v3.1.1

that's it. A Github action will

• build
• create a release
• update the package on pipy.