aoc_day4_2020.py

import re

REQUIRED_KEYS = [
    'byr',
    'iyr',
    'eyr',
    'hgt',
    'hcl',
    'ecl',
    'pid'
]

passports = []
current_passport = ""
for line in INPUT.split("\n"):
    if line == "":
        passports.append(dict([kv.split(":") for kv in current_passport.strip().split(" ")]))
        current_passport = ""
    else:
        current_passport += " " + line

# Part 1
print(len([p for p in passports if  set(REQUIRED_KEYS).issubset(set(p.keys()))]))


# Part 2
def is_valid(p):
    if not set(REQUIRED_KEYS).issubset(set(p.keys())):
        return False

    if not re.match(r'^\d\d\d\d$', p['byr']):
        return False
    if not 1920 <= int(p['byr']) <= 2002:
        return False
    if not re.match(r'^\d\d\d\d$', p['iyr']):
        return False
    if not 2010 <= int(p['iyr']) <= 2020:
        return False
    if not re.match(r'^\d\d\d\d$', p['eyr']):
        return False
    if not 2020 <= int(p['eyr']) <= 2030:
        return False
    m = re.match(r'(\d+)(cm|in)', p['hgt'])
    if not m:
        return False
    height, type = m.groups()
    if type == 'cm':
        if not 150 <= int(height) <= 193:
            return False
    elif type == 'in':
        if not 59 <= int(height) <= 76:
            return False
    if not re.match(r'^#[0-9a-f]{6}$', p['hcl']):
        return False
    if p['ecl'] not in ['amb','blu','brn','gry','grn','hzl','oth']:
        return False
    if not re.match(r'^[0-9]{9}$', p['pid']):
        return False
    return True


print(len([p for p in passports if is_valid(p)]))