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| author | Arthur de Jong <arthur@arthurdejong.org> | 2012-02-11 21:09:06 +0100 |
|---|---|---|
| committer | Arthur de Jong <arthur@arthurdejong.org> | 2012-02-11 21:09:06 +0100 |
| commit | 8a10861e780d65dbda3bd08db42da058cf03c976 (patch) | |
| tree | e2fd1493396ab2f54121a36038209e9989dde259 | |
| parent | a3610a31dfbd0873c56ae0c8e318f57359a5354d (diff) | |
add a PVN (Pievienotās vērtības nodokļa, Latvian VAT number) module
git-svn-id: http://arthurdejong.org/svn/python-stdnum/python-stdnum@116 9dea7c4f-944c-4273-ac1a-574ede026edc
| -rw-r--r-- | README | 1 | ||||
| -rw-r--r-- | stdnum/__init__.py | 1 | ||||
| -rw-r--r-- | stdnum/lv/__init__.py | 0 | ||||
| -rw-r--r-- | stdnum/lv/pvn.py | 103 | ||||
| -rw-r--r-- | tests/test_robustness.doctest | 1 |
5 files changed, 106 insertions, 0 deletions
@@ -33,6 +33,7 @@ Currently this package supports the following formats: * FPA, ΦΠΑ (Foros Prostithemenis Aksias, the Greek VAT number) * Ust ID Nr. (Umsatzsteur Identifikationnummer, the German VAT number) * BTW, TVA, NWSt (Belgian VAT number) + * PVN (Pievienotās vērtības nodokļa, Latvian VAT number) * IMEI (International Mobile Equipment Identity) * IMSI (International Mobile Subscriber Identity) * MEID (Mobile Equipment Identifier) diff --git a/stdnum/__init__.py b/stdnum/__init__.py index 8a0a0c3..246b548 100644 --- a/stdnum/__init__.py +++ b/stdnum/__init__.py @@ -47,6 +47,7 @@ Currently this package supports the following formats: * FPA, ΦΠΑ (Foros Prostithemenis Aksias, the Greek VAT number) * Ust ID Nr. (Umsatzsteur Identifikationnummer, the German VAT number) * BTW, TVA, NWSt (Belgian VAT number) + * PVN (Pievienotās vērtības nodokļa, Latvian VAT number) * IMEI (International Mobile Equipment Identity) * IMSI (International Mobile Subscriber Identity) * MEID (Mobile Equipment Identifier) diff --git a/stdnum/lv/__init__.py b/stdnum/lv/__init__.py new file mode 100644 index 0000000..e69de29 --- /dev/null +++ b/stdnum/lv/__init__.py diff --git a/stdnum/lv/pvn.py b/stdnum/lv/pvn.py new file mode 100644 index 0000000..8a13424 --- /dev/null +++ b/stdnum/lv/pvn.py @@ -0,0 +1,103 @@ +# pvn.py - functions for handling Latvian PVN (VAT) numbers +# coding: utf-8 +# +# Copyright (C) 2012 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 + +"""Module for handling Latvian PVN (Pievienotās vērtības nodokļa, VAT) +numbers. + +It is a 11 digit number that can either be a reference to a legal entity +(in which case the first digit > 3) or a natural person (in which case it +should be the same as the personal code (personas kods)). Personal codes +start with 6 digits to denote the birth date in the form ddmmyy. + +>>> compact('LV 4000 3521 600') +'40003521600' +>>> is_valid('40003521600') +True +>>> is_valid('40003521601') # invalid check digit +False +>>> is_valid('161175-19997') # personal code +True +>>> is_valid('161375-19997') # invalid date +False +""" + +import datetime + +from stdnum.util import clean + + +# validation functions are available on-line but it is not allowed +# to perform automated queries: +# http://www6.vid.gov.lv/VID_PDB?aspxerrorpath=/vid_pdb/pvn.asp + + +def compact(number): + """Convert the number to the minimal representation. This strips the + number of any valid separators and removes surrounding whitespace.""" + number = clean(number, ' -').upper().strip() + if number.startswith('LV'): + number = number[2:] + return number + + +def checksum(number): + """Calculate the checksum for legal entities.""" + weights = (9, 1, 4, 8, 3, 10, 2, 5, 7, 6, 1) + return sum(weights[i] * int(n) for i, n in enumerate(number)) % 11 + + +def calc_check_digit_pers(number): + """Calculate the check digit for personal codes. The number passed + should not have the check digit included.""" + # note that this algorithm has not been confirmed by an independent source + weights = (10, 5, 8, 4, 2, 1, 6, 3, 7, 9) + check = 1 + sum(weights[i] * int(n) for i, n in enumerate(number)) + return str(check % 11 % 10) + + +def get_birth_date(number): + """Split the date parts from the number and return the birth date.""" + day = int(number[0:2]) + month = int(number[2:4]) + year = int(number[4:6]) + year += 1800 + int(number[6]) * 100 + return datetime.date(year, month, day) + + +def is_valid(number): + """Checks to see if the number provided is a valid VAT number. This checks + the length, formatting and check digit.""" + try: + number = compact(number) + except: + return False + if len(number) != 11 or not number.isdigit(): + return False + if number[0] > '3': + # legal entity + return checksum(number) == 3 + else: + # natural resident, check if birth date is valid + try: + birth_date = get_birth_date(number) + # TODO: check that the birth date is not in the future + except ValueError, e: + return False + return calc_check_digit_pers(number[:-1]) == number[-1] diff --git a/tests/test_robustness.doctest b/tests/test_robustness.doctest index 3a3e665..b118dfa 100644 --- a/tests/test_robustness.doctest +++ b/tests/test_robustness.doctest @@ -35,6 +35,7 @@ invalid junk. >>> from stdnum.fr import siren >>> from stdnum.gr import vat as gr_vat >>> from stdnum.iso7064 import mod_11_10, mod_11_2, mod_37_2, mod_37_36, mod_97_10 +>>> from stdnum.lv import pvn >>> from stdnum.nl import bsn, onderwijsnummer, btw >>> from stdnum.us import ssn |