How to give points for each indices of list - python-3.x

Question

def voting_borda(rank_ballots):
'''(list of list of str) -> tuple of (str, list of int)
The parameter is a list of 4-element lists that represent rank ballots for a single riding.
The Borda Count is determined by assigning points according to ranking. A party gets 3 points for each first-choice ranking, 2 points for each second-choice ranking and 1 point for each third-choice ranking. (No points are awarded for being ranked fourth.) For example, the rank ballot shown above would contribute 3 points to the Liberal count, 2 points to the Green count and 1 point to the CPC count. The party that receives the most points wins the seat.
Return a tuple where the first element is the name of the winning party according to Borda Count and the second element is a four-element list that contains the total number of points for each party. The order of the list elements corresponds to the order of the parties in PARTY_INDICES.
#>>> voting_borda([['GREEN','NDP', 'LIBERAL', 'CPC'], ['GREEN','CPC','LIBERAL','NDP'],
['LIBERAL','NDP', 'CPC', 'GREEN']])
#('GREEN',[4, 6, 5, 3])
list_of_party_order = []
for sublist in rank_ballots:
for party in sublist[0]:
if party == 'GREEN':
GREEN_COUNT += 3
elif party == 'NDP':
NDP_COUNT += 3
elif party == 'LIBERAL':
LIBERAL_COUNT += 3
elif party == 'CPC':
CPC_COUNT += 3
for party in sublist[1]:
if party == 'GREEN':
GREEN_COUNT += 2
elif party == 'NDP':
NDP_COUNT += 2
elif party == 'LIBERAL':
LIBERAL_COUNT += 2
elif party == 'CPC':
CPC_COUNT += 2
for party in sublist[2]:
if party == 'GREEN':
GREEN_COUNT += 1
elif party == 'NDP':
NDP_COUNT += 1
elif party == 'LIBERAL':
LIBERAL_COUNT += 1
elif party == 'CPC':
CPC_COUNT += 1
I don't know how I would give points for each indices of the list MORE SIMPLY.
Can someone please help me? Without being too complicated. Thank you!

Answer 1

This does not do EXACTLY what you were asking for, it returns a tuple with two values: winner's name, and a dictionary of all parties and their values, instead of a list with only values. In my opinion, this is better for almost any case, and if you don't like it, you can convert it to a list.
It also takes multiple parameters instead of one list too, but you can change that by simply removing the * from *args
Notice, however, if you care about speed rather than small code, this is not the best way to do it. It does work, tho.
It is also superior to your code in the manner of this allowing you to NOT use any of the parties names or amount of parties inside the function, which makes it possible to add, rename or remove parties.
def voting_borda(*args):
results = {}
for sublist in args:
for i in range(0, 3):
if sublist[i] in results:
results[sublist[i]] += 3-i
else:
results[sublist[i]] = 3-i
winner = max(results, key=results.get)
return winner, results
print(voting_borda(
['GREEN','NDP', 'LIBERAL', 'CPC'],
['GREEN','CPC','LIBERAL','NDP'],
['LIBERAL','NDP', 'CPC', 'GREEN']
))
Will result into: ('GREEN', {'LIBERAL': 5, 'NDP': 4, 'GREEN': 6, 'CPC': 3})

Answer 2

I found your voting simulation assignment online and added a few of the constants from it here to simplify the code for solving the problem a little (although it may not look like it with their definitions at the beginning).
The first element of the tuple returned is not exactly in the requested format -- it's a list rather than a single value -- to deal with the quite real possibility of tie votes, as illustrated with the sample data values used below for rank_ballots. Even if there wasn't a tie, the element is return is a singleton list -- which actually is usually easier to deal with than having it vary depending on there's more than one or not.
PARTY_NAMES = ['NDP', 'GREEN', 'LIBERAL', 'CPC']
NAME_TO_INDEX = {party:PARTY_NAMES.index(party) for party in PARTY_NAMES}
INDEX_TO_NAME = {PARTY_NAMES.index(party):party for party in PARTY_NAMES}
def voting_borda(rank_ballots):
results = [0 for _ in PARTY_NAMES]
MAX_POINTS = len(PARTY_NAMES)-1
for ballot in rank_ballots:
for i,party in enumerate(ballot):
results[NAME_TO_INDEX[party]] += MAX_POINTS-i
highest_rank = max(results)
winners = [INDEX_TO_NAME[i] for i,total in enumerate(results) if total == highest_rank]
return winners, results
rank_ballots = [['GREEN','NDP', 'LIBERAL', 'CPC'],
['GREEN','CPC','LIBERAL','NDP'],
['LIBERAL', 'GREEN', 'NDP', 'CPC'],
['LIBERAL','NDP', 'CPC', 'GREEN'],]
print(voting_borda(rank_ballots))
Output:
(['GREEN', 'LIBERAL'], [5, 8, 8, 3])