https://github.com/bradbeattie/python-vote-core

Python libraries for various electoral methods
https://github.com/bradbeattie/python-vote-core

Last synced: 21 days ago
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Python libraries for various electoral methods

• Host: GitHub
• URL: https://github.com/bradbeattie/python-vote-core
• Owner: bradbeattie
• License: other
• Created: 2009-12-14T07:03:14.000Z (almost 16 years ago)
• Default Branch: master
• Last Pushed: 2021-12-25T02:27:16.000Z (almost 4 years ago)
• Last Synced: 2025-05-07T14:58:47.758Z (6 months ago)
• Language: Python
• Homepage: http://modernballots.com
• Size: 224 KB
• Stars: 141
• Watchers: 13
• Forks: 36
• Open Issues: 14
• Metadata Files:
  • Readme: README.rst
  • Changelog: CHANGES.rst
  • License: LICENSE.txt

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README

          
Python Vote Core

================

python-vote-core implements various electoral methods, providing the results

calculated off a provided set of ballots and options.

* Project page: http://github.com/bradbeattie/python-vote-core

* Issue tracker: http://github.com/bradbeattie/python-vote-core/issues

* Example usage: http://modernballots.com

Methods implemented

-------------------

* Single Winner Methods

  * Plurality (aka first-past-the-post or fptp)

  * Instant-Runoff Voting (aka IRV)

  * Schulze Method (aka Beatpath)

* Multiple Winner Methods

  * Plurality at large (aka block voting)

  * Single Transferable Vote (aka STV)

  * Schulze STV

* Ordering Methods

  * Schulze Proportional Representation

  * Schulze Nonproportional Representation

Basic Usage

-----------

Schulze method example::

    >>> from pyvotecore.schulze_method import SchulzeMethod

    >>> from pyvotecore.condorcet import CondorcetHelper

    >>> ballots = [

    ...   { "count":3, "ballot":[["A"], ["C"], ["D"], ["B"]] },

    ...   { "count":9, "ballot":[["B"], ["A"], ["C"], ["D"]] },

    ...   { "count":8, "ballot":[["C"], ["D"], ["A"], ["B"]] },

    ...   { "count":5, "ballot":[["D"], ["A"], ["B"], ["C"]] },

    ...   { "count":5, "ballot":[["D"], ["B"], ["C"], ["A"]] }

    ... ]

    >>> SchulzeMethod(ballots, ballot_notation = CondorcetHelper.BALLOT_NOTATION_GROUPING).as_dict()

    {'actions': [{'edges': {('A', 'B')}},

      {'edges': {('A', 'C')}},

      {'nodes': {'A'}},

      {'edges': {('B', 'C')}},

      {'nodes': {'B', 'D'}}],

     'candidates': {'A', 'B', 'C', 'D'},

     'pairs': {('A', 'B'): 16,

      ('A', 'C'): 17,

      ('A', 'D'): 12,

      ('B', 'A'): 14,

      ('B', 'C'): 19,

      ('B', 'D'): 9,

      ('C', 'A'): 13,

      ('C', 'B'): 11,

      ('C', 'D'): 20,

      ('D', 'A'): 18,

      ('D', 'B'): 21,

      ('D', 'C'): 10},

     'strong_pairs': {('A', 'B'): 16,

      ('A', 'C'): 17,

      ('B', 'C'): 19,

      ('C', 'D'): 20,

      ('D', 'A'): 18,

      ('D', 'B'): 21},

     'winner': 'C'}