122 lines
3.6 KiB
Python
122 lines
3.6 KiB
Python
# pyRCV2: Preferential vote counting
|
|
# Copyright © 2020–2021 Lee Yingtong Li (RunasSudo)
|
|
#
|
|
# This program is free software: you can redistribute it and/or modify
|
|
# it under the terms of the GNU Affero General Public License as published by
|
|
# the Free Software Foundation, either version 3 of the License, or
|
|
# (at your option) any later version.
|
|
#
|
|
# This program is distributed in the hope that it will be useful,
|
|
# but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
# GNU Affero General Public License for more details.
|
|
#
|
|
# You should have received a copy of the GNU Affero General Public License
|
|
# along with this program. If not, see <https://www.gnu.org/licenses/>.
|
|
|
|
__pragma__ = lambda x: None
|
|
|
|
from pyRCV2.numbers import Num
|
|
|
|
class Candidate:
|
|
def __init__(self, name):
|
|
self.name = name
|
|
|
|
def __repr__(self):
|
|
return '<Candidate ' + self.name + '>'
|
|
|
|
def toString(self):
|
|
return repr(self)
|
|
|
|
class CandidateState:
|
|
HOPEFUL = 0
|
|
PROVISIONALLY_ELECTED = 10
|
|
DISTRIBUTING_SURPLUS = 20
|
|
ELECTED = 30
|
|
EXCLUDING = 40
|
|
EXCLUDED = 50
|
|
WITHDRAWN = 60
|
|
|
|
class Ballot:
|
|
def __init__(self, value, preferences):
|
|
self.value = value
|
|
self.preferences = preferences
|
|
|
|
def clone(self):
|
|
return Ballot(self.value, self.preferences)
|
|
|
|
class Election:
|
|
"""
|
|
Represents a BLT election
|
|
"""
|
|
|
|
def __init__(self, name='', seats=0, candidates=None, ballots=None, withdrawn=None):
|
|
self.name = name
|
|
self.seats = seats
|
|
self.candidates = candidates if candidates is not None else []
|
|
self.ballots = ballots if ballots is not None else []
|
|
self.withdrawn = withdrawn if withdrawn is not None else []
|
|
|
|
class CountCard:
|
|
"""
|
|
Represents a Candidate's (or exhausted pile) current progress in the count
|
|
"""
|
|
def __init__(self):
|
|
self.orig_votes = Num('0')
|
|
self.transfers = Num('0')
|
|
self.state = CandidateState.HOPEFUL
|
|
self.order_elected = None # Negative for order of exclusion
|
|
|
|
# self.parcels = List[Parcel]
|
|
# Parcel = List[Tuple[Ballot, Num]]
|
|
# The exhausted/loss to fraction piles will have only one parcel
|
|
self.parcels = []
|
|
self._parcels_sorted = False # Optimisation to avoid re-sorting in exclusion by_value
|
|
|
|
@property
|
|
def votes(self):
|
|
__pragma__('opov')
|
|
return self.orig_votes + self.transfers
|
|
__pragma__('noopov')
|
|
|
|
def step(self):
|
|
"""Roll over previous round transfers in preparation for next round"""
|
|
self.orig_votes = self.votes
|
|
self.transfers = Num('0')
|
|
|
|
def clone(self):
|
|
"""Return a clone of this count card (including cloning ballots) as a record of this stage"""
|
|
result = CountCard()
|
|
result.orig_votes = self.orig_votes
|
|
result.transfers = self.transfers
|
|
result.parcels = [[(b[0].clone(), b[1]) for b in p] for p in self.parcels]
|
|
result.state = self.state
|
|
result.order_elected = self.order_elected
|
|
return result
|
|
|
|
class CountStepResult:
|
|
def __init__(self, comment, candidates, exhausted, loss_fraction, total, quota, vote_required_election):
|
|
self.comment = comment
|
|
|
|
self.candidates = candidates # SafeDict: Candidate -> CountCard
|
|
self.exhausted = exhausted # CountCard
|
|
self.loss_fraction = loss_fraction # CountCard
|
|
|
|
self.total = total
|
|
self.quota = quota
|
|
self.vote_required_election = vote_required_election
|
|
|
|
def clone(self):
|
|
"""Return a clone of this result as a record of this stage"""
|
|
|
|
candidates = SafeDict()
|
|
for c, cc in self.candidates.items():
|
|
__pragma__('opov')
|
|
candidates[c] = cc.clone()
|
|
__pragma__('noopov')
|
|
|
|
return CountStepResult(self.comment, candidates, self.exhausted.clone(), self.loss_fraction.clone(), self.total, self.quota)
|
|
|
|
class CountCompleted(CountStepResult):
|
|
pass
|