adventofcode2020/day4b.py

import re

def valid(ppt):
    k = ppt.keys()
    for v in ["byr", "iyr", "eyr", "hgt", "hcl", "ecl", "pid"]:
        if v not in k:
            print(f"Missing {v}.")
            return False
    byr = ppt["byr"]
    byrm = re.match(r"^(\d{4})$", byr)
    if byrm == None:
        print(f"Bad BYR: {byr}.")
        return False
    byrn = int(byrm[1])
    if byrn < 1920 or byrn > 2002:
        print(f"Bad BYR: {byr}.")
        return False
    iyr = ppt["iyr"]
    iyrm = re.match(r"^(\d{4})$", iyr)
    if iyrm == None:
        print(f"Bad IYR: {iyr}.")
        return False
    iyrn = int(iyrm[1])
    if iyrn < 2010 or iyrn > 2020:
        print(f"Bad IYR: {iyr}.")
        return False
    eyr = ppt["eyr"]
    eyrm = re.match(r"^(\d{4})$", eyr)
    if eyrm == None:
        print(f"Bad EYR: {eyr}.")
        return False
    eyrn = int(eyrm[1])
    if eyrn < 2020 or eyrn > 2030:
        print(f"Bad EYR: {eyr}.")
        return False
    hgt = ppt["hgt"]
    hgtm = re.match(r"^(\d{2,3})(cm|in)$", hgt)
    if hgtm == None:
        print(f"Bad HGT: {hgt}.")
        return False
    hgtn = int(hgtm[1])
    hgtu = hgtm[2]
    if (hgtu == "cm" and (hgtn < 150 or hgtn > 193)) or (hgtu == "in" and (hgtn < 59 or hgtn > 76)):
        print(f"Bad HGT: {hgt}.")
        return False
    hcl = ppt["hcl"]
    if re.search(r"^#[0-9a-f]{6}$", hcl) == None:
        print(f"Bad HCL: {hcl}.")
        return False
    ecl = ppt["ecl"]
    if ecl not in ["amb", "blu", "brn", "gry", "grn", "hzl", "oth"]:
        print(f"Bad ECL: {ecl}.")
        return False
    pid = ppt["pid"]
    if re.search(r"^[0-9]{9}$", pid) == None:
        print(f"Bad PID: {pid}.")
        return False

    return True

def main():
    with open("input4.txt") as file:
        text = file.read()
    ppts = text.split("\n\n")
    print(f"I have {len(ppts)} passports.")
    count = 0
    cinv = 0
    for ppt in ppts:
        ppt = ppt.replace("\n", " ")
        pptchunks = ppt.split(" ")
        pptdct = {}
        for chunk in pptchunks:
            if chunk != "":
                bits = chunk.split(":")
                pptdct[bits[0]] = bits[1]
        if valid(pptdct):
            count += 1
        else:
            cinv += 1
    print(f"There are {count} valid passports and {cinv} invalid ones.")

if __name__ == "__main__":
    main()