| from django.utils.encoding import smart_str, smart_unicode |
| |
| def ssn_check_digit(value): |
| "Calculate Italian social security number check digit." |
| ssn_even_chars = { |
| '0': 0, '1': 1, '2': 2, '3': 3, '4': 4, '5': 5, '6': 6, '7': 7, '8': 8, |
| '9': 9, 'A': 0, 'B': 1, 'C': 2, 'D': 3, 'E': 4, 'F': 5, 'G': 6, 'H': 7, |
| 'I': 8, 'J': 9, 'K': 10, 'L': 11, 'M': 12, 'N': 13, 'O': 14, 'P': 15, |
| 'Q': 16, 'R': 17, 'S': 18, 'T': 19, 'U': 20, 'V': 21, 'W': 22, 'X': 23, |
| 'Y': 24, 'Z': 25 |
| } |
| ssn_odd_chars = { |
| '0': 1, '1': 0, '2': 5, '3': 7, '4': 9, '5': 13, '6': 15, '7': 17, '8': |
| 19, '9': 21, 'A': 1, 'B': 0, 'C': 5, 'D': 7, 'E': 9, 'F': 13, 'G': 15, |
| 'H': 17, 'I': 19, 'J': 21, 'K': 2, 'L': 4, 'M': 18, 'N': 20, 'O': 11, |
| 'P': 3, 'Q': 6, 'R': 8, 'S': 12, 'T': 14, 'U': 16, 'V': 10, 'W': 22, |
| 'X': 25, 'Y': 24, 'Z': 23 |
| } |
| # Chars from 'A' to 'Z' |
| ssn_check_digits = [chr(x) for x in range(65, 91)] |
| |
| ssn = value.upper() |
| total = 0 |
| for i in range(0, 15): |
| try: |
| if i % 2 == 0: |
| total += ssn_odd_chars[ssn[i]] |
| else: |
| total += ssn_even_chars[ssn[i]] |
| except KeyError: |
| msg = "Character '%(char)s' is not allowed." % {'char': ssn[i]} |
| raise ValueError(msg) |
| return ssn_check_digits[total % 26] |
| |
| def vat_number_check_digit(vat_number): |
| "Calculate Italian VAT number check digit." |
| normalized_vat_number = smart_str(vat_number).zfill(10) |
| total = 0 |
| for i in range(0, 10, 2): |
| total += int(normalized_vat_number[i]) |
| for i in range(1, 11, 2): |
| quotient , remainder = divmod(int(normalized_vat_number[i]) * 2, 10) |
| total += quotient + remainder |
| return smart_unicode((10 - total % 10) % 10) |
