Approval-based committee rules (ABC rules) are voting methods for selecting a committee, i.e., a fixed-size subset of candidates. ABC rules are also known as approval-based multi-winner rules. The input of such rules are approval ballots. We recommend the book (Multi-Winner Voting with Approval Preferences) by Lackner and Skowron [2] as a detailed introduction to ABC rules and related research directions. In addition, the survey by Faliszewski et al. [1] is useful as a more general introduction to committee voting (not limited to approval ballots).
The following ABC rules are implemented:
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Approval Voting (AV)
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Satisfaction Approval Voting (SAV)
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Proportional Approval Voting (PAV)
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Sequential Proportional Approval Voting (seq-PAV)
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Reverse Sequential Proportional Approval Voting (revseq-PAV)
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Approval Chamberlin-Courant (CC)
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Phragmén's sequential rule
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Monroe's rule
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Minimax Approval Voting (MAV)
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Greedy Monroe
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Method of Equal Shares (Rule X)
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Phragmén's First Method (Eneström's Method)
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and many more ...
As simple as:
pip install abcvotingFurther details can be found here.
Install all dependencies including development requirements and the abcvoting package in development mode:
pip install -e .[dev]Basic unit tests can be run by excluding tests which require additional dependencies:
pytest -m "not mipgurobi and not gmpy2 and not slow" tests/For development, configure the black formatter and pre-commit hooks - see below. Also installing all optional dependencies is recommended.
A development package is build for every commit on the master branch and uploaded to the test instance of PyPI. It can be installed using the following command:
python3 -m pip install --index-url https://test.pypi.org/simple/ --extra-index-url https://pypi.org/simple abcvotingCode needs to be formatted using the black formatter. This is checked by Github actions. Configure your editor to run the black formatter.
Pre-commit hooks are not required, but they are recommended for development.
Pre-commit is used to manage and maintain pre-commit hooks. Install
pre-commit (e.g. via apt, conda or pip) and then run $ pre-commit install to install the hooks.
[1] Piotr Faliszewski, Piotr Skowron, Arkadii Slinko, and Nimrod Talmon. Multiwinner voting: A new challenge for social choice theory. In Ulle Endriss, editor, Trends in Computational Social Choice, chapter 2, pages 27–47. AI Access, 2017. http://research.illc.uva.nl/COST-IC1205/BookDocs/Chapters/TrendsCOMSOC-02.pdf
[2] Lackner, Martin, and Piotr Skowron. "Multi-Winner Voting with Approval Preferences". arXiv preprint arXiv:2007.01795. 2020. https://arxiv.org/abs/2007.01795