# nid.py - functions for handling Mauritian national ID numbers # coding: utf-8 # # Copyright (C) 2018 Arthur de Jong # # This library is free software; you can redistribute it and/or # modify it under the terms of the GNU Lesser General Public # License as published by the Free Software Foundation; either # version 2.1 of the License, or (at your option) any later version. # # This library is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU # Lesser General Public License for more details. # # You should have received a copy of the GNU Lesser General Public # License along with this library; if not, write to the Free Software # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA # 02110-1301 USA """ID number (Mauritian national identifier). The Mauritian national ID number is a unique 14 alphanumeric identifier assigned at birth to identify individuals. It is displayed on the National Identity Card. The number consists of one alphabetic character and thirteen digits: * the first character of the person's surname at birth * 2 digits for day of birth * 2 digits for month of birth * 2 digits for year of birth * 6 digit unique id * a check digit More information: * http://mnis.govmu.org/English/ID%20Card/Pages/default.aspx """ import datetime import re from stdnum.exceptions import * from stdnum.util import clean _nid_re = re.compile('^[A-Z][0-9]+[0-9A-Z]$') # characters used for checksum calculation _alphabet = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ' def compact(number): """Convert the number to the minimal representation. This strips surrounding whitespace and separation dash.""" return clean(number, ' ').upper().strip() def calc_check_digit(number): """Calculate the check digit for the number.""" check = sum((14 - i) * _alphabet.index(n) for i, n in enumerate(number[:13])) return _alphabet[(17 - check) % 17] def _get_date(number): """Convert the part of the number that represents a date into a datetime. Note that the century may be incorrect.""" day = int(number[1:3]) month = int(number[3:5]) year = int(number[5:7]) try: return datetime.date(year + 2000, month, day) except ValueError: raise InvalidComponent() def validate(number): """Check if the number is a valid ID number.""" number = compact(number) if len(number) != 14: raise InvalidLength() if not _nid_re.match(number): raise InvalidFormat() if calc_check_digit(number) != number[-1]: raise InvalidChecksum() _get_date(number) return number def is_valid(number): """Check if the number provided is a valid RFC.""" try: return bool(validate(number)) except ValidationError: return False