Croatian (Hrvatski) IBAN control number checker

gistfile1.py

#!/usr/bin/env python
"""
This script is primarily used to get the IBAN number for Croatian account numbers
"""
import os

import sys

def get_iso13616_numbers(chars):
    out = ""
    chars = str(chars)
    for char in chars:
        char = char.upper()
        char_num = ord(char)
        out += str(char_num-55) # capital A is 65 and equals 10 in ISO13616
    return out

def get_iban_number(country, account_number):
    number = str(account_number)
    number += get_iso13616_numbers(country)
    number += "00"
    assert(len(number) == 23)
    int_num = int(number)
    remainder = int_num % 97
    control = 97 + 1 - remainder
    if control < 10:
       control = "0" + str(control)
    control = str(control)
    print "Control number = %s" % control

    test = str(account_number)
    test += get_iso13616_numbers(country)
    test += control
    int_test = int(test)
    print "Check = %s (should be 1)" % (int_test % 97)
    if int_test % 97 != 1:
       print "Test error"
    else:
       print "Test OK"
       print "Full IBAN = %s%s%s" % (country, str(control), str(account_number))

if __name__ == '__main__':
    if len(sys.argv) == 3:
        country = sys.argv[1]
        number = sys.argv[2]
        sys.exit(get_iban_number(country, number))
    else:
        sys.stderr.write("Not enough arguments ... usage: %s <country> <account_number>\n" % sys.argv[0])
        sys.exit(254)