Simple shredder for Opavote BLT format ranked choice ballots

opavote_ranked_ballot_counter.py

#!/usr/bin/env python3

import sys

with open(sys.argv[1], 'r') as ballot_file:
    lines = [line.rstrip() for line in ballot_file]

# Trim first header and final line
lines.pop(0)
lines.pop()

ballots = []
options = []

is_ballot = True
for x in lines:
    if x == "0":
        is_ballot = False
        continue
    if is_ballot:
        ranking = x.split(" ")
        first = ranking.pop(0)
        if first != "1":
            print("Expected first thing in ballot to be 1")
            sys.exit()
        last = ranking.pop()
        if last != "0":
            print("Expected last thing in ballot to be 0")
            sys.exit()

        ranking = [int(x) for x in ranking]
        ballots.append(ranking)
    else:
        options.append(x)

def count_in_ballots(thing):
    count = 0
    for b in ballots:
        if thing in b:
            count += 1
    return count

def count_first(thing):
    count = 0
    for b in ballots:
        if len(b) == 0:
            continue
        if thing == b[0]:
            count += 1
    return count

for index, o in enumerate(options):
    option_number = index + 1
    percentage_on_ballots = count_in_ballots(option_number) / len(ballots) * 100.0
    percentage_first_on_ballots = count_first(option_number) / len(ballots) * 100.0
    print(f"Option {option_number}: {o} had {percentage_on_ballots:.2f}% participation and was {percentage_first_on_ballots:.2f}% of voter's first choice")