Algoritmo que valida o número do cartão de cidadão em Python. Explicação do algoritmo aqui: https://www.autenticacao.gov.pt/documents/10179/11463/Validação+de+Número+de+Documento+do+Cartão+de+Cidadão/0dbc446b-3718-41e5-b982-551a72f8b8a8

validarcc.py

def main():
    cartao = input("Introduza o número do cartão\n")
    print("Cartão inválido") if validateCC(cartao) == 0 else print("Cartão válido")

def getNumberFromChar(letra):
    charDict = {
        "0" : "0",
        "1" : "1",
        "2" : "2",
        "3" : "3",
        "4" : "4",
        "5" : "5",
        "6" : "6",
        "7" : "7",
        "8" : "8",
        "9" : "9",
        "A" : "10",
        "B" : "11",
        "C" : "12",
        "D" : "13",
        "E" : "14",
        "F" : "15",
        "G" : "16",
        "H" : "17",
        "I" : "18",
        "J" : "19",
        "K" : "20",
        "L" : "21",
        "M" : "22",
        "N" : "23",
        "O" : "24",
        "P" : "25",
        "Q" : "26",
        "R" : "27",
        "S" : "28",
        "T" : "29",
        "U" : "30",
        "V" : "31",
        "W" : "32",
        "X" : "33",
        "Y" : "34",
        "Z" : "35",
    }
    return int(charDict[letra])

def validateCC(str):
    upperCaseStr = str.upper()
    sum = 0
    secondDigit = 0

    if len(str) != 12:
        return 0

    for i in range(len(str) - 1, -1, -1):
        valor = getNumberFromChar(upperCaseStr[i])
        if secondDigit == 1:
            valor = valor * 2
            if valor > 9:
                valor = valor - 9
        sum = sum + valor
        secondDigit = 1 if secondDigit == 0 else 0

    return (sum % 10) == 0

if __name__ == '__main__':
    main()