pref_voting 1.13.21

pref_voting is a Python package that contains tools to reason about elections and margin graphs, and implementations of voting methods.

pref_voting

Installation

With pip package manager:

pip install pref_voting

Documentation

Online documentation is available at https://pref-voting.readthedocs.io.

Example Usage

A profile (of linear orders over the candidates) is created by initializing a Profile class object. Simply provide a list of rankings (each ranking is a tuple of numbers) and a list giving the number of voters with each ranking:

from pref_voting.profiles import Profile

rankings = [
    (0, 1, 2, 3), 
    (2, 3, 1, 0), 
    (3, 1, 2, 0), 
    (1, 2, 0, 3), 
    (1, 3, 2, 0)]

rcounts = [5, 3, 2, 4, 3]

prof = Profile(rankings, rcounts=rcounts)

The function generate_profile is used to generate a profile for a given number of candidates and voters:

from pref_voting.generate_profiles import generate_profile

# generate a profile using the Impartial Culture probability model
prof = generate_profile(3, 4) # prof is a Profile object

# generate a profile using the Impartial Anonymous Culture probability model
prof = generate_profile(3, 4, probmod = "IAC") # prof is a Profile object 

To use one of the many voting methods, import the function from pref_voting.voting_methods and apply it to the profile:

from pref_voting.generate_profiles import generate_profile
from pref_voting.voting_methods import *

prof = generate_profile(3, 4)
split_cycle(prof) # returns the sorted list of winning candidates
split_cycle.display(prof) # display the winning candidates

Questions?

Feel free to send an email if you have questions about the project.

License

MIT