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

poetry

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

Anaconda 3 + Python 3.12 is supposed to be installed

Poetry and Anaconda (recommended)

To create quetzal_env automatically and install quetzal, open anaconda prompt and run windows-install batch file

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

press enter to accept default environment name or enter a custom name

If you are facing SSL issues

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

security warning: the host is added to pip.ini

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

Tests

to run unittest:

poetry run python -W ignore -m unittest discover

Deploying

1. change the version in pyproject.toml

[tool.poetry]
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.