Source code for whalrus.rules.rule_coombs

# -*- coding: utf-8 -*-
Copyright Sylvain Bouveret, Yann Chevaleyre and Fran├žois Durand,,

This file is part of Whalrus.

Whalrus is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

Whalrus is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with Whalrus.  If not, see <>.
from whalrus.rules.rule import Rule
from whalrus.rules.rule_iterated_elimination import RuleIteratedElimination
from whalrus.rules.rule_veto import RuleVeto
from whalrus.eliminations.elimination import Elimination
from whalrus.eliminations.elimination_last import EliminationLast

[docs]class RuleCoombs(RuleIteratedElimination): """ Coombs' rule. Parameters ---------- args Cf. parent class. base_rule : Rule Default: :class:`RuleVeto`. elimination : Elimination Default: :class:`EliminationLast` with ``k=1``. kwargs Cf. parent class. Examples -------- At each round, the candidate with the worst Veto score is eliminated. >>> rule = RuleCoombs(['a > b > c', 'b > a > c', 'c > a > b'], weights=[2, 3, 4]) >>> rule.eliminations_[0].rule_.gross_scores_ {'a': 0, 'b': -4, 'c': -5} >>> rule.eliminations_[1].rule_.gross_scores_ {'a': -3, 'b': -6} >>> rule.eliminations_[2].rule_.gross_scores_ {'a': -9} >>> rule.winner_ 'a' """ def __init__(self, *args, base_rule: Rule = None, elimination: Elimination = None, **kwargs): if base_rule is None: base_rule = RuleVeto() if elimination is None: elimination = EliminationLast(k=1) super().__init__(*args, base_rule=base_rule, elimination=elimination, **kwargs)