113 lines
3.6 KiB
Python
113 lines
3.6 KiB
Python
# hetu.py - functions for handling Finnish personal identity codes
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# coding: utf-8
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#
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# Copyright (C) 2011 Jussi Judin
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# Copyright (C) 2012, 2013 Arthur de Jong
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#
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# This library is free software; you can redistribute it and/or
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# modify it under the terms of the GNU Lesser General Public
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# License as published by the Free Software Foundation; either
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# version 2.1 of the License, or (at your option) any later version.
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#
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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# Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
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# 02110-1301 USA
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"""HETU (Henkilötunnus, Finnish personal identity code).
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Module for handling Finnish personal identity codes (HETU, Henkilötunnus).
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See http://www.vaestorekisterikeskus.fi/default.aspx?id=45 for checksum
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calculation details and http://tarkistusmerkit.teppovuori.fi/tarkmerk.htm#hetu1
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for historical details.
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>>> validate('131052-308T')
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'131052-308T'
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>>> validate('131052-308U')
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Traceback (most recent call last):
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...
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InvalidChecksum: ...
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>>> validate('310252-308Y')
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Traceback (most recent call last):
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...
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InvalidComponent: ...
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>>> compact('131052a308t')
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'131052A308T'
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"""
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import re
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import datetime
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from stdnum.exceptions import *
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from stdnum.util import clean
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_century_codes = {
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'+': 1800,
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'-': 1900,
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'A': 2000,
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}
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# Finnish personal identity codes are composed of date part, century
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# indicating sign, individual number and control character.
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# ddmmyyciiiC
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_hetu_re = re.compile(r'^(?P<day>[0123]\d)(?P<month>[01]\d)(?P<year>\d\d)'
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r'(?P<century>[-+A])(?P<individual>\d\d\d)'
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r'(?P<control>[0-9ABCDEFHJKLMNPRSTUVWXY])$')
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def compact(number):
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"""Convert the HETU to the minimal representation. This strips
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surrounding whitespace and converts it to upper case."""
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return clean(number, '').upper().strip()
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def _calc_checksum(number):
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return '0123456789ABCDEFHJKLMNPRSTUVWXY'[int(number) % 31]
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def validate(number):
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"""Checks to see if the number provided is a valid HETU. It checks the
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format, whether a valid date is given and whether the check digit is
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correct."""
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number = compact(number)
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match = _hetu_re.search(number)
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if not match:
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raise InvalidFormat()
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day = int(match.group('day'))
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month = int(match.group('month'))
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year = int(match.group('year'))
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century = _century_codes[match.group('century')]
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individual = int(match.group('individual'))
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# check if birth date is valid
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try:
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datetime.date(century + year, month, day)
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except ValueError:
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raise InvalidComponent()
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# for historical reasons individual IDs start from 002
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if individual < 2:
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raise InvalidComponent()
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checkable_number = '%02d%02d%02d%03d' % (day, month, year, individual)
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if match.group('control') != _calc_checksum(checkable_number):
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raise InvalidChecksum()
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return number
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def is_valid(number):
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"""Checks to see if the number provided is a valid HETU. It checks the
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format, whether a valid date is given and whether the check digit is
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correct."""
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try:
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return bool(validate(number))
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except ValidationError:
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return False
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# This is here just for completeness as there are no different length forms
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# of Finnish personal identity codes:
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format = compact
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