aoc-2020-python-day2.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, 'password': password})
  return s


def valid_pwd(p):
  return p['spec'][0] <= Counter(p['password'])[p['letter']] <= p['spec'][1]


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