advent_10_part2.py

scores = {
  ')': 1,
  ']': 2,
  '}': 3,
  '>': 4
}

expected = {
  '(': ')',
  '[': ']',
  '{': '}',
  '<': '>'
}

def score(line):
  current_score = 0
  stack = []
  for char in line:
    if char in expected.keys():
      stack.append(char)
    else:
      if char == expected[stack[-1]]:
        stack.pop()
      else:
        return current_score
  while stack:
    current_score *= 5
    current_score += scores[expected[stack.pop()]]
  return current_score

if __name__ == '__main__':
  with open('input.txt') as data:
    final_scores = []
    for line in data:
      line = line.strip()
      total_score = score(line)
      if total_score:
        final_scores.append(total_score)
    print(sorted(final_scores)[len(final_scores) // 2])