def __init__(self,
datestr,
pollster,
sponsor,
sample_size,
con, lab, lib, ukip):
"""Constructor. Store off data."""
# Store off the easy stuff.
self.pollster = pollster
self.sponsor = sponsor
self.sample_size = sample_size
# Parse the date string into a date object for easy sorting.
self.date = datetime.datetime.strptime(datestr, '%d %b %Y')
# Store all the vote percentages as if they were votes from a total
# turnout of 100.
votes = {CON: con,
LAB: lab,
LD: lib,
UKP: ukip}
votes[OTH] = 100 - sum(votes.values())
# Now convert those into a support dictionary.
self.support = utils.calculate_support(votes)
# Initialize somewhere to store the MonteCarlo results of this poll.
self.mc_results = None
return
def calculate_overall_support(self, year=None):
"""Create a support dictionary based on the number of votes in the
given year. If no year is provided, use the predicted votes.
"""
total_votes = {}
for const_name in self.constituencies.keys():
const = self.constituencies[const_name]
if year is None:
votes = const.sim_votes
elif year == 2005:
votes = const.votes_2005
else:
assert year == 2010, "Year must be None, 2005 or 2010"
votes = const.votes_2010
for party in votes.keys():
if party not in total_votes.keys():
total_votes[party] = votes[party]
else:
total_votes[party] += votes[party]
support = utils.calculate_support(total_votes)
return support
def __init__(self, datestr, pollster, sponsor, sample_size, con, lab, lib,
ukip):
"""Constructor. Store off data."""
# Store off the easy stuff.
self.pollster = pollster
self.sponsor = sponsor
self.sample_size = sample_size
# Parse the date string into a date object for easy sorting.
self.date = datetime.datetime.strptime(datestr, '%d %b %Y')
# Store all the vote percentages as if they were votes from a total
# turnout of 100.
votes = {CON: con, LAB: lab, LD: lib, UKP: ukip}
votes[OTH] = 100 - sum(votes.values())
# Now convert those into a support dictionary.
self.support = utils.calculate_support(votes)
# Initialize somewhere to store the MonteCarlo results of this poll.
self.mc_results = None
return
def calculate_overall_support(self, year=None):
"""Create a support dictionary based on the number of votes in the
given year. If no year is provided, use the predicted votes.
"""
total_votes = {}
for const_name in self.constituencies.keys():
const = self.constituencies[const_name]
if year is None:
votes = const.sim_votes
elif year == 2005:
votes = const.votes_2005
else:
assert year == 2010, "Year must be None, 2005 or 2010"
votes = const.votes_2010
for party in votes.keys():
if party not in total_votes.keys():
total_votes[party] = votes[party]
else:
total_votes[party] += votes[party]
support = utils.calculate_support(total_votes)
return support
def analyze(self):
"""Analyze the results of the election."""
# Create a new Result structure to hold these results.
self.result = Result()
# First determine the largest party.
party_list = sorted(self.parties.values(),
key=attrgetter('seats'),
reverse=True)
self.result.largest_party = party_list[0].name
self.result.most_seats_won = party_list[0].seats
# Save off the numbers of seats gained by all parties.
for party in self.parties:
self.result.seats[party] = self.parties[party].seats
# Record zero seats for any party that didn't get any.
for party in (set(PARTY_NAMES) - set(self.parties)):
self.result.seats[party] = 0
# Now determine whether the largest party is past or behind the winning
# line (and by how much).
self.result.margin_of_victory = (self.result.most_seats_won -
NEEDED_FOR_MAJORITY)
if self.result.margin_of_victory >= 0:
self.result.summary = "{0} victory (majority {1})".format(
self.result.largest_party,
self.result.margin_of_victory)
self.result.winner = self.result.largest_party
else:
self.result.summary = "Hung Parliament ({0} needs {1})".format(
self.result.largest_party,
(0 - self.result.margin_of_victory))
# Work out the coalitions that could conceivably take power. The
# expected rules for this are as follows:
# - A coalition always has CON or LAB as the senior partner
# - Both CON and LAB will take LD as their preferred junior partner
# - Only CON will take UKP as a junior partner
# - Only LAB will take GRN as a junior partner
# - LD and GRN will not join a coalition that includes UKP
# - SNP will join neither a LAB nor a CON coalition
# - PC will join only a LAB coalition
# - OTH will join anyone
# - Both LAB and CON prefer named parties to OTH
if (self.result.seats[CON] + self.result.seats[LD] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-LD")
elif (self.result.seats[CON] + self.result.seats[UKP] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-UKP")
elif (self.result.seats[CON] + self.result.seats[LD] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-LD-OTH")
elif (self.result.seats[CON] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-OTH")
elif (self.result.seats[CON] + self.result.seats[UKP] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-UKP-OTH")
if (self.result.seats[LAB] + self.result.seats[LD] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[PC] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-GRN")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[PC] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-GRN")
elif (self.result.seats[LAB] + self.result.seats[PC] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-PC")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[PC] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-GRN-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[PC] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-GRN-OTH")
if len(self.result.possible_coalitions) == 0:
self.result.possible_coalitions = ["NONE"]
# Did UKIP win any seats in this election?
if UKP in self.parties:
self.result.ukip_seats = self.parties[UKP].seats
else:
self.result.ukip_seats = 0
# Did the Lib-Dems?
if LD in self.parties:
self.result.libdem_seats = self.parties[LD].seats
else:
self.result.libdem_seats = 0
# Did the Greens hold Brighton Pavilion?
if self.constituencies["Brighton Pavilion"].winning_party == GRN:
self.result.greens_hold_brighton = True
else:
self.result.greens_hold_brighton = False
# Was the party with the most seats the popular vote winner?
votes = {}
for const_name in self.constituencies:
const = self.constituencies[const_name]
for party in const.sim_votes.keys():
if party not in votes.keys():
votes[party] = const.sim_votes[party]
else:
votes[party] += const.sim_votes[party]
most_votes = 0
self.result.most_votes_party = None
for party in votes.keys():
if votes[party] > most_votes:
most_votes = votes[party]
self.result.most_votes_party = party
self.result.seat_winner_is_pop_winner = (self.result.largest_party ==
self.result.most_votes_party)
# Find all the constituencies where the Conservatives are predicted
# to win heavily, but UKIP did not field a candidate in 2010 - these
# are the UKIP stealth targets, where they could win much more
# easily than expected.
no_ukips = [self.constituencies[cons] for cons in self.constituencies if
self.constituencies[cons].votes_2010[UKP] == 0]
con_win_no_ukip = [cons for cons in no_ukips if
cons.winning_party == CON]
for cons in con_win_no_ukip:
vote_counts = sorted(cons.sim_votes.values(),
reverse=True)
margin = vote_counts[0] - vote_counts[1]
if margin > 1000:
self.result.ukip_stealth_targets[cons.name] = margin
# Was the vote distribution sufficiently close to the initial support
# figures?
overall_support = utils.calculate_support(votes)
support_2010 = self.calculate_overall_support(2010)
self.result.support = overall_support
for party in self.predicted_support:
divergence = abs(self.predicted_support[party] -
overall_support[party])
logger.debug("{0} support was {1}, predicted {2}, actual {3}, "
"divergence {4}".format(party,
support_2010[party],
self.predicted_support[party],
overall_support[party],
divergence))
if divergence > RESULT_TOLERANCE:
# This party's result is too far away from its predicted
# support. This result can't stand.
logger.debug("Result too far from prediction!")
self.result.result_too_divergent = True
return
def analyze(self):
"""Analyze the results of the election."""
# Create a new Result structure to hold these results.
self.result = Result()
# First determine the largest party.
party_list = sorted(self.parties.values(),
key=attrgetter('seats'),
reverse=True)
self.result.largest_party = party_list[0].name
self.result.most_seats_won = party_list[0].seats
# Save off the numbers of seats gained by all parties.
for party in self.parties:
self.result.seats[party] = self.parties[party].seats
# Record zero seats for any party that didn't get any.
for party in (set(PARTY_NAMES) - set(self.parties)):
self.result.seats[party] = 0
# Now determine whether the largest party is past or behind the winning
# line (and by how much).
self.result.margin_of_victory = (self.result.most_seats_won -
NEEDED_FOR_MAJORITY)
if self.result.margin_of_victory >= 0:
self.result.summary = "{0} victory (majority {1})".format(
self.result.largest_party, self.result.margin_of_victory)
self.result.winner = self.result.largest_party
else:
self.result.summary = "Hung Parliament ({0} needs {1})".format(
self.result.largest_party, (0 - self.result.margin_of_victory))
# Work out the coalitions that could conceivably take power. The
# expected rules for this are as follows:
# - A coalition always has CON or LAB as the senior partner
# - Both CON and LAB will take LD as their preferred junior partner
# - Only CON will take UKP as a junior partner
# - Only LAB will take GRN as a junior partner
# - LD and GRN will not join a coalition that includes UKP
# - SNP will join neither a LAB nor a CON coalition
# - PC will join only a LAB coalition
# - OTH will join anyone
# - Both LAB and CON prefer named parties to OTH
if (self.result.seats[CON] + self.result.seats[LD] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-LD")
elif (self.result.seats[CON] + self.result.seats[UKP] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-UKP")
elif (self.result.seats[CON] + self.result.seats[LD] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-LD-OTH")
elif (self.result.seats[CON] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-OTH")
elif (self.result.seats[CON] + self.result.seats[UKP] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("CON-UKP-OTH")
if (self.result.seats[LAB] + self.result.seats[LD] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[PC] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-GRN")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[PC] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-GRN")
elif (self.result.seats[LAB] + self.result.seats[PC] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-PC")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[PC] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[OTH] >=
NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-GRN-OTH")
elif (self.result.seats[LAB] + self.result.seats[LD] +
self.result.seats[GRN] + self.result.seats[PC] +
self.result.seats[OTH] >= NEEDED_FOR_MAJORITY):
self.result.possible_coalitions.append("LAB-LD-PC-GRN-OTH")
if len(self.result.possible_coalitions) == 0:
self.result.possible_coalitions = ["NONE"]
# Did UKIP win any seats in this election?
if UKP in self.parties:
self.result.ukip_seats = self.parties[UKP].seats
else:
self.result.ukip_seats = 0
# Did the Lib-Dems?
if LD in self.parties:
self.result.libdem_seats = self.parties[LD].seats
else:
self.result.libdem_seats = 0
# Did the Greens hold Brighton Pavilion?
if self.constituencies["Brighton Pavilion"].winning_party == GRN:
self.result.greens_hold_brighton = True
else:
self.result.greens_hold_brighton = False
# Was the party with the most seats the popular vote winner?
votes = {}
for const_name in self.constituencies:
const = self.constituencies[const_name]
for party in const.sim_votes.keys():
if party not in votes.keys():
votes[party] = const.sim_votes[party]
else:
votes[party] += const.sim_votes[party]
most_votes = 0
self.result.most_votes_party = None
for party in votes.keys():
if votes[party] > most_votes:
most_votes = votes[party]
self.result.most_votes_party = party
self.result.seat_winner_is_pop_winner = (
self.result.largest_party == self.result.most_votes_party)
# Find all the constituencies where the Conservatives are predicted
# to win heavily, but UKIP did not field a candidate in 2010 - these
# are the UKIP stealth targets, where they could win much more
# easily than expected.
no_ukips = [
self.constituencies[cons] for cons in self.constituencies
if self.constituencies[cons].votes_2010[UKP] == 0
]
con_win_no_ukip = [
cons for cons in no_ukips if cons.winning_party == CON
]
for cons in con_win_no_ukip:
vote_counts = sorted(cons.sim_votes.values(), reverse=True)
margin = vote_counts[0] - vote_counts[1]
if margin > 1000:
self.result.ukip_stealth_targets[cons.name] = margin
# Was the vote distribution sufficiently close to the initial support
# figures?
overall_support = utils.calculate_support(votes)
support_2010 = self.calculate_overall_support(2010)
self.result.support = overall_support
for party in self.predicted_support:
divergence = abs(self.predicted_support[party] -
overall_support[party])
logger.debug("{0} support was {1}, predicted {2}, actual {3}, "
"divergence {4}".format(party, support_2010[party],
self.predicted_support[party],
overall_support[party],
divergence))
if divergence > RESULT_TOLERANCE:
# This party's result is too far away from its predicted
# support. This result can't stand.
logger.debug("Result too far from prediction!")
self.result.result_too_divergent = True
return
