Advent of code 2021 day 16

def process1(s, part2=False):
  s = ''.join(f'{int(nibble, 16):04b}' for nibble in s.strip())
  operation_for_id = {
      0: lambda *operands: sum(operands),
      1: lambda *operands: np.prod(operands),
      2: lambda *operands: min(operands),
      3: lambda *operands: max(operands),
      5: lambda operand1, operand2: int(operand1 > operand2),
      6: lambda operand1, operand2: int(operand1 < operand2),
      7: lambda operand1, operand2: int(operand1 == operand2),
  }
  sum_versions = 0

  def read_bits(n):
    nonlocal s
    value = int(s[:n], 2)
    s = s[n:]
    return value

  def parse():
    nonlocal sum_versions
    version = read_bits(3)
    sum_versions += version
    id = read_bits(3)
    if id == 4:
      number = 0
      more = True
      while more:
        more = read_bits(1)
        number = number * 16 + read_bits(4)
      return number
    operands = []
    length_type = read_bits(1)
    if length_type == 0:
      num_bits = read_bits(15)
      len0 = len(s)
      while len0 - len(s) != num_bits:
        operands.append(parse())
    else:
      num_packets = read_bits(11)
      for _ in range(num_packets):
        operands.append(parse())
    return operation_for_id[id](*operands)

  result = parse()
  return result if part2 else sum_versions