aoc-2020-python-day2-part2.py

from collections import Counter


def get_input():
  with open('2.txt') as f:
    passwords = f.readlines()
  return map(str.strip, passwords)


def get_password_specs(specs):
  s = []
  for p in specs:
    spec, letter, password = p.split(' ')
    spec = list(map(int, spec.partition('-')[0:3:2]))
    s.append({'letter': letter[:1], 'spec': spec, 'pwd': password})
  return s


def valid_pwd(p):
  idx1, idx2 = p['spec']
  return (p['pwd'][idx1-1] == p['letter']) != (p['pwd'][idx2-1] == p['letter'])


def run():
  print(len([p for p in get_password_specs(get_input()) if valid_pwd(p)]))


if __name__ == '__main__':
  run()