95 lines
3.2 KiB
Python
95 lines
3.2 KiB
Python
|
# tva.py - functions for handling French TVA numbers
|
|||
|
|
# coding: utf-8
|
|||
|
|
#
|
|||
|
|
# Copyright (C) 2012, 2013 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
|
|||
|
|
|
|||
|
|
"""n° TVA (taxe sur la valeur ajoutée, French VAT number).
|
|||
|
|
|
|||
|
|
The n° TVA (Numéro d'identification à la taxe sur la valeur ajoutée) is the
|
|||
|
|
SIREN (Système d’Identification du Répertoire des Entreprises) prefixed by
|
|||
|
|
two digits. In old style numbers the two digits are numeric, with new
|
|||
|
|
style numbers at least one is a alphabetic.
|
|||
|
|
|
|||
|
|
>>> compact('Fr 40 303 265 045')
|
|||
|
|
'40303265045'
|
|||
|
|
>>> validate('23334175221')
|
|||
|
|
'23334175221'
|
|||
|
|
>>> validate('84 323 140 391')
|
|||
|
|
Traceback (most recent call last):
|
|||
|
|
...
|
|||
|
|
InvalidChecksum: ...
|
|||
|
|
>>> validate('K7399859412') # new-style number
|
|||
|
|
'K7399859412'
|
|||
|
|
>>> validate('4Z123456782') # new-style number starting with digit
|
|||
|
|
'4Z123456782'
|
|||
|
|
"""
|
|||
|
|
|
|||
|
|
from stdnum.exceptions import *
|
|||
|
|
from stdnum.fr import siren
|
|||
|
|
from stdnum.util import clean
|
|||
|
|
|
|||
|
|
|
|||
|
|
# the valid characters for the first two digits (O and I are missing)
|
|||
|
|
_alphabet = '0123456789ABCDEFGHJKLMNPQRSTUVWXYZ'
|
|||
|
|
|
|||
|
|
|
|||
|
|
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('FR'):
|
|||
|
|
number = number[2:]
|
|||
|
|
return number
|
|||
|
|
|
|||
|
|
|
|||
|
|
def validate(number):
|
|||
|
|
"""Checks to see if the number provided is a valid VAT number. This
|
|||
|
|
checks the length, formatting and check digit."""
|
|||
|
|
number = compact(number)
|
|||
|
|
if not all(x in _alphabet for x in number[:2]):
|
|||
|
|
raise InvalidFormat()
|
|||
|
|
if len(number) != 11:
|
|||
|
|
raise InvalidLength()
|
|||
|
|
siren.validate(number[2:])
|
|||
|
|
if number.isdigit():
|
|||
|
|
# all-numeric digits
|
|||
|
|
if int(number[:2]) != (int(number[2:] + '12') % 97):
|
|||
|
|
raise InvalidChecksum()
|
|||
|
|
else:
|
|||
|
|
# one of the first two digits isn't a number
|
|||
|
|
if number[0].isdigit():
|
|||
|
|
check = (
|
|||
|
|
_alphabet.index(number[0]) * 24 +
|
|||
|
|
_alphabet.index(number[1]) - 10)
|
|||
|
|
else:
|
|||
|
|
check = (
|
|||
|
|
_alphabet.index(number[0]) * 34 +
|
|||
|
|
_alphabet.index(number[1]) - 100)
|
|||
|
|
if (int(number[2:]) + 1 + check // 11) % 11 != (check % 11):
|
|||
|
|
raise InvalidChecksum()
|
|||
|
|
return number
|
|||
|
|
|
|||
|
|
|
|||
|
|
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:
|
|||
|
|
return bool(validate(number))
|
|||
|
|
except ValidationError:
|
|||
|
|
return False
|