130 lines
4.6 KiB
Python
130 lines
4.6 KiB
Python
# vat.py - functions for handling European VAT numbers
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# coding: utf-8
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#
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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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"""VAT (European Union VAT number).
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The European Union VAT number consists of a 2 letter country code (ISO
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3166-1, except Greece which uses EL) followed by a number that is
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allocated per country.
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The exact format of the numbers varies per country and a country-specific
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check is performed on the number using the VAT module that is relevant for
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that country.
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>>> compact('ATU 57194903')
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'ATU57194903'
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>>> validate('BE697449992')
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'BE0697449992'
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>>> validate('FR 61 954 506 077')
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'FR61954506077'
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>>> guess_country('00449544B01')
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['nl']
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"""
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from stdnum.exceptions import *
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from stdnum.util import clean
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country_codes = set([
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'at', 'be', 'bg', 'cy', 'cz', 'de', 'dk', 'ee', 'es', 'fi', 'fr', 'gb',
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'gr', 'hu', 'ie', 'it', 'lt', 'lu', 'lv', 'mt', 'nl', 'pl', 'pt', 'ro',
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'se', 'si', 'sk'
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])
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"""The collection of country codes that are queried. Greece is listed with
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a country code of gr while for VAT purposes el is used instead."""
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_country_modules = dict()
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vies_wsdl = 'http://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl'
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"""The WSDL URL of the VAT Information Exchange System (VIES)."""
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# a cached version of the suds client for VIES
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_vies_client = None
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def _get_cc_module(cc):
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"""Get the VAT number module based on the country code."""
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# Greece uses a "wrong" country code
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cc = cc.lower()
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if cc == 'el':
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cc = 'gr'
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if cc not in country_codes:
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return
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if cc not in _country_modules:
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# do `from stdnum.CC import vat` instead of `import stdnum.CC.vat`
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# to handle the case where vat is an alias
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_country_modules[cc] = __import__(
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'stdnum.%s' % cc, globals(), locals(), ['vat']).vat
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return _country_modules[cc]
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def compact(number):
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"""Convert the number to the minimal representation. This strips the
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number of any valid separators and removes surrounding whitespace."""
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number = clean(number, '').upper().strip()
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module = _get_cc_module(number[:2])
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if not module:
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raise InvalidComponent()
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return number[:2] + module.compact(number[2:])
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def validate(number):
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"""Checks to see if the number provided is a valid VAT number. This
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performs the country-specific check for the number."""
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number = clean(number, '').upper().strip()
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module = _get_cc_module(number[:2])
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if not module:
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raise InvalidComponent()
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return number[:2] + module.validate(number[2:])
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def is_valid(number):
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"""Checks to see if the number provided is a valid VAT number. This
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performs the country-specific check for the number."""
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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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def guess_country(number):
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"""Guess the country code based on the provided number. This checks the
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provided number against each of the validation routines and returns
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the list of countries for which it is valid. This returns lower case
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codes and returns gr (not el) for Greece."""
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return [cc
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for cc in country_codes
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if _get_cc_module(cc).is_valid(number)]
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def check_vies(number): # pragma: no cover (no tests for this function)
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"""Queries the online European Commission VAT Information Exchange
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System (VIES) for validity of the provided number. Note that the
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service has usage limitations (see the VIES website for details).
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This returns a dict-like object."""
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# this function isn't automatically tested because it would require
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# network access for the tests and unnecessarily load the VIES website
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number = compact(number)
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global _vies_client
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if not _vies_client:
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from suds.client import Client
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from urllib import getproxies
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_vies_client = Client(vies_wsdl, proxy=getproxies())
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return _vies_client.service.checkVat(number[:2], number[2:])
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