pref_voting 0.1.21

pref_voting is a Python packaging that contains tools to reason about election profiles and margin graphs, and implementations of a variety of preferential voting methods.

pref_voting

Installation

With pip package manager:

pip install pref_voting

Documentation

Online documentation is available at https://pref_voting.readthedocs.io.

Profiles and Voting Methods

A profile (of linear orders over the candidates) is created by initializing a Profile class object. This needs a list of rankings (each ranking is a tuple of numbers), the number of candidates, and a list giving the number of each ranking in the profile:

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 

from pref_voting.profiles import Profile
from pref_voting.voting_methods import *

prof = Profile(rankings, num_cands, rcounts=rcounts)
print(f"{split_cycle.name} winners:  {split_cycle(prof)}")
split_cycle.display(prof)

Versions

• v0.1.10 (2022-08-09): Initial release
• v0.1.13 (2022-11-05): Minor updates and bug fixes
• v0.1.14 (2022-12-19): Add plurality_scores to ProfileWithTies; add generate ceots function; bug fixes
• v0.1.21 (2022-12-27): Add instant_runoff_for_truncated_linear_orders and functions to truncate overvotes in a ProfileWithTies

Questions?

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

License

MIT