AOC2020D04.py

import pprint

def get_puzzle_input(a_file_name: str) -> list[dict[str, str]]:
    passport = dict()
    passports: list[dict[str, str]] = []
    passport_chunks: list[str] = []

    def get_passport(a_passport_chunks: list[str]) -> dict[str, str]:
        passport_line = ' '.join(a_passport_chunks)
        return {x[0] : x[1] for x in (t.split(':') for t in passport_line.split()) }

    with open(a_file_name) as INFILE:
        passport_lines = [line.strip() for line in INFILE]

    for passport_line in passport_lines:
        if passport_line == '':
            passports.append(get_passport(passport_chunks))
            passport_chunks = []
        else:
            passport_chunks.append(passport_line)

    if passport_chunks:
        passports.append(get_passport(passport_chunks))

    return passports

def is_valid_field(a_passport_field_name: str, a_passport_field_value: str) -> bool:
    is_valid: bool = False

    match a_passport_field_name:
        case 'byr':
            if len(a_passport_field_value) != 4:
                return False

            try:
                byr = int(a_passport_field_value)
                return True if 1920 <= byr <= 2002 else False
            except ValueError:
                return False
        case 'iyr':
            if len(a_passport_field_value) != 4:
                return False

            try:
                byr = int(a_passport_field_value)
                return True if 2010 <= byr <= 2020 else False
            except ValueError:
                return False
        case 'eyr':
            if len(a_passport_field_value) != 4:
                return False

            try:
                byr = int(a_passport_field_value)
                return True if 2020 <= byr <= 2030 else False
            except ValueError:
                return False
        case 'hgt':

            try:
                hgt = int(a_passport_field_value[:-2])
            except ValueError:
                return False

            if a_passport_field_value.endswith('cm'):
                if 150 <= hgt <= 193:
                    return True

            if a_passport_field_value.endswith('in'):
                if 59 <= hgt <= 76:
                    return True

        case 'hcl':
            hcl_set = {'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' }

            if len(a_passport_field_value) != 7:
                return False

            if (a_passport_field_value[0] == '#'
                and all(hcl_suffix_char in hcl_set for hcl_suffix_char in a_passport_field_value[1:])):

                return True

        case 'ecl':
            if a_passport_field_value in ['amb', 'blu', 'brn', 'gry', 'grn', 'hzl', 'oth']:
                return True

        case 'pid':
            if len(a_passport_field_value) == 9:
                try:
                    _ = int(a_passport_field_value)
                    return True
                except ValueError:
                    return False

        case 'cid':
            return True

    return is_valid

def is_valid_passport(a_passport: dict[str, str], a_p1_check: bool = True) -> bool:
    is_valid: bool = False

    if (len(a_passport) >= 7
        and all(k in a_passport for k in ['byr', 'iyr', 'eyr', 'hgt', 'hcl', 'ecl', 'pid'])):

            if a_p1_check:
                is_valid = True
            else:
                if (is_valid_field('byr', a_passport['byr'])
                    and is_valid_field('iyr', a_passport['iyr'])
                    and is_valid_field('eyr', a_passport['eyr'])
                    and is_valid_field('hgt', a_passport['hgt'])
                    and is_valid_field('hcl', a_passport['hcl'])
                    and is_valid_field('ecl', a_passport['ecl'])
                    and is_valid_field('pid', a_passport['pid'])):

                    is_valid = True

    return is_valid

passports = get_puzzle_input('aoc_2020/aoc_2020_day_04.txt')

print(f"p1={sum([is_valid_passport(passport) for passport in passports])}")
print(f"p2={sum([is_valid_passport(passport, a_p1_check=False) for passport in passports])}")