Wild predictions for the Swedish election of 2018

election.py

import itertools
import os
import operator
import colorama
from colorama import Fore, Back, Style

colorama.init()

#os.system("cls")
class Party:
    def __init__(self, name, likes, votes, style):
        self.name = name
        self.likes = likes
        self.votes = votes
        self.style = style

    def __repr__(self):
        return Style.BRIGHT + self.style + self.name.upper() + Style.RESET_ALL

    def nonstyled_str(self):
        return self.name.upper()

class Combination:
    def __init__(self, parties, like_value, chance_of_50):
        self.parties = sorted(parties, key=operator.attrgetter('votes'))
        self.parties.reverse()
        self.like_value = like_value
        self.chance_of_50 = chance_of_50

    def chance(self):
        return self.like_value * self.chance_of_50

    def total_votes(self):
        return sum([p.votes for p in self.parties])

    def __lt__(self, other):
        return self.chance() < other.chance()
        #return self.total_votes() < other.total_votes()

    def __repr__(self):
        partylist = ", ".join([str(p) for p in self.parties])
        partylist_nonstyled = ", ".join([p.nonstyled_str() for p in self.parties])
        partylist_padding = " " * (20 - len(partylist_nonstyled))
        score = 100 * self.chance()
        total_votes_str = "%10.1f" % self.total_votes()
        if self.total_votes() > 45:
            total_votes_str = Style.BRIGHT + getattr(Fore, "YELLOW") + total_votes_str + Style.RESET_ALL
        return "%s %s %8.0f %s %%" % (partylist, partylist_padding, score, total_votes_str)


parties = []

pv  = Party( "v", {"s":  1,   "c": 0.6, "l": 0.3, "mp": 1},                         7.9, getattr(Fore, "RED"))
ps  = Party( "s", {"kd": 0.1, "m": 0.2, "v": 0.7, "mp": 1,   "l":  0.4, "c": 0.5},  28.4, getattr(Fore, "RED"))
pmp = Party("mp", {"m":  0.3, "v": 0.5, "s": 1,   "c":  0.6, "l":  0.5},            4.3, getattr(Fore, "GREEN"))
psd = Party("sd", {"kd": 1,   "m": 1,   "l": 0.5, "c":  0.5, "s":  0.2},            17.6, getattr(Fore, "YELLOW"))
pc  = Party( "c", {"kd": 0.7, "m": 1,   "l": 1,   "s":  0.6, "mp": 0.5},            8.6, getattr(Fore, "MAGENTA"))
pm  = Party( "m", {"kd": 1,   "c": 1,   "l": 1,   "s":  0.2, "sd": 0.6, "mp": 0.7}, 19.8, getattr(Fore, "BLUE"))
pl  = Party( "l", {"kd": 0.5, "c": 1,   "m": 1,   "s":  0.6, "mp": 0.7},            5.5, getattr(Fore, "MAGENTA"))
pkd = Party("kd", {"sd": 0.8, "c": 1,   "m": 1,   "l":  1,   "s": 0.5,  "mp": 0.8}, 6.4, getattr(Fore, "BLUE"))

parties.append(psd)
parties.append(pv)
parties.append(ps)
parties.append(pmp)
parties.append(pkd)
parties.append(pc)
parties.append(pm)
parties.append(pl)

for p1 in parties:
    for p2 in parties:
        if p1 != p2:
            if not p2.name in p1.likes:
                p1.likes[p2.name] = 0.001
                print(p1.name , p2.name)

combinations = []
for comb_size in range(3, len(parties)+1):
    for ps in itertools.combinations(parties, comb_size):
        like_value = 1
        for p1 in ps:
            for p2 in ps:
                if p1 == p2:
                    continue
                mutual_like = min(p1.likes[p2.name], p2.likes[p1.name])
                like_value *= mutual_like
        total_votes = sum([p.votes for p in ps])
        chance_of_50 = total_votes - 30
        print(ps, like_value, total_votes, chance_of_50)
        if like_value < 0.00000001:
            continue
        if chance_of_50 < 10:
            continue
        combo = Combination(ps, like_value, chance_of_50)
        combinations.append(combo)

combinations.sort()
combinations.reverse()

print("")
print("PARTIES                  SCORE      TOTAL_VOTES" )
print("--------------------|------------|--------------")
for c in combinations[:15]:
    print(c)
print("")

With pre-election poll numbers, here's the output:

PARTIES                  SCORE      TOTAL_VOTES
-----------------------|----------|-------------
S, C, M                 28.67       51.2 %
S, M, L                 23.30       49.1 %
S, MP, M                19.46       47.6 %
S, C, M, L               7.25       57.7 %
S, KD, M                 5.31       48.3 %
S, MP, C, M              3.25       56.2 %
S, MP, M, L              2.08       54.1 %
SD, KD, M, L             2.07       49.0 %
S, KD, C, M              1.11       56.9 %
S, KD, M, L              0.55       54.8 %
V, S, M                  0.50       52.6 %
SD, C, M                 0.34       45.4 %
SD, KD, C, M             0.28       51.1 %
S, MP, C, M, L           0.26       62.7 %
SD, S, M                 0.22       61.7 %

Day-after-election votes (plus tweaks to numbers/algo)

PARTIES                  SCORE      TOTAL_VOTES
--------------------|------------|--------------
V, S, MP               678.40       40.6 %
C, M, L                390.00       33.9 %
KD, C, M               235.20       34.8 %
KD, C, M, L            181.69       40.3 %
SD, KD, M              141.31       43.8 %
S, MP, C               101.70       41.3 %
KD, M, L                61.20       31.7 %
S, C, M                 60.30       56.8 %
S, C, L                 50.00       42.5 %
S, M, L                 34.13       53.7 %
S, MP, L                32.80       38.2 %
S, MP, M                18.22       52.5 %
S, C, M, L              11.63       62.3 %
MP, C, M                 8.75       32.7 %
MP, C, M, L              6.64       38.2 %
S, MP, C, L              6.05       46.8 %
S, KD, C                 1.64       43.4 %

After tweaking a few numbers and fixing some output prettyfication, here are the results:

(Yellow means >45% )