ΘΕΜΑ: Project : Αποδείξεις - Έλεγχος ορθότητας ΑΦΜ

def calculate_afm(afm):
    """ Calculates the integrity of the personal tax number.
        Author: marmako@gmail.com
 
    """
 
    if len(afm) != 9:
        print("Το ΑΦΜ: {0} δεν είναι έγκυρο.\nΠρέπει να έχει \
        εννέα ψηφία.".format(afm))
        return False
 
    if afm.isdigit() == False:
        print("Το ΑΦΜ: {0} δεν είναι έγκυρο.\nΠρέπει να αποτελείται από \
        ψηφία.".format(afm))
        return False
 
    chcknumbers = [0, 2, 4, 8, 16, 32, 64, 128, 256]
    lchcknumbers = len(chcknumbers)-1
    sum = 0
 
    for i in range(9):
        sum = sum + (int(afm[i]) * chcknumbers[lchcknumbers])
        lchcknumbers -= 1
 
    ch_digit = int(afm[8])  
 
    ypoloipo = sum % 11
 
    if ypoloipo == 10:
        ypoloipo = 0
 
    if ypoloipo == ch_digit :
        return True
    else:
        return False
 
if __name__=='__main__':
    print(calculate_afm('000555248'))
 

def check_afm(afm):
    """ 
    Checks the integrity of the personal tax number.
 
    Author: marmako@gmail.com
    """
    if afm.isdigit() == False:
        msg  = "Το ΑΦΜ: {0} δεν είναι έγκυρο.\n".format(afm)
        msg += "Πρέπει να αποτελείται ΜΟΝΟ από ψηφία."
        print(msg)
        return False
 
    elif len(afm) != 9:
        msg  = "Το ΑΦΜ: {0} δεν είναι έγκυρο.\n".format(afm)
        msg += "Πρέπει να έχει εννέα ψηφία."
        print(msg)
        return False
 
    else:
        chck_numbers = [256, 128, 64, 32, 16, 8, 4, 2, 1]
        length = len(chck_numbers) - 1
        athroisma = 0
 
        for i in range(length):
            athroisma += (int(afm[i]) * chck_numbers[i])
 
        ch_digit = int(afm[-1])  
 
        ypoloipo = (athroisma % 11) % 10
 
        if ypoloipo == ch_digit :
            return True
        else:
            return False
 
if __name__ == '__main__':
    print(check_afm('000555248')) # Ακυρο ΑΦΜ
    print(check_afm('000555240')) # Εγκυρο ΑΦΜ

def check_afm(afm):
    """ Checks the integrity of the personal tax number
 
    Author: marmako@gmail.com
 
    """
 
    # the error messages (convention: the start with msg_)
    msg_invalid = "Το ΑΦΜ {} δεν είναι έγκυρο.\n".format(afm)
    msg_specific = None
 
    # check what may be wrong, with an explanatory message (msg_specific)
    if not afm.isdigit():
        msg_specific = "Πρέπει να αποτελείται ΜΟΝΟ από ψηφία."
    elif not len(afm) == 9:
        msg_specific = "Πρέπει να έχει εννέα ψηφία."
    else:
        # the algorithm of validating an ΑΦΜ
        # we split the number in two parts
        # head contains all the digits but the last one in reverse order
        head_of_afm = afm[-2::-1]
        check_digit = afm[-1]
 
        total = 0
        for i, d in enumerate(head_of_afm):
            total += int(d) * 2 ** (i + 1)
 
        if (total % 11) % 10 != int(check_digit):
            msg_specific = "ΤΟ ΑΦΜ απέτυχε στον έλεγχο ορθότητας."
 
 
    # handle the errors
    if msg_specific is not None:
        print(msg_invalid + msg_specific)
        return False
 
    # if nothing goes wrong
    return True
 
def main():
    # Valid ΑΦΜ
    afms = ["011111111", "000555240"]
    for afm in afms:
        check_afm(afm)
 
 
    # Invalid ΑΦΜ
    afm = "000555248"
    check_afm(afm)
 
if __name__ == '__main__':
    main()