71 lines
2.2 KiB
Python
71 lines
2.2 KiB
Python
# kmkr.py - functions for handling Estonian VAT numbers
|
|
# coding: utf-8
|
|
#
|
|
# Copyright (C) 2012-2015 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
|
|
|
|
"""KMKR (Käibemaksukohuslase, Estonian VAT number).
|
|
|
|
>>> compact('EE 100 931 558')
|
|
'100931558'
|
|
>>> validate('100594102')
|
|
'100594102'
|
|
>>> validate('100594103') # incorrect check digit
|
|
Traceback (most recent call last):
|
|
...
|
|
InvalidChecksum: ...
|
|
"""
|
|
|
|
from stdnum.exceptions import *
|
|
from stdnum.util import clean
|
|
|
|
|
|
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('EE'):
|
|
number = number[2:]
|
|
return number
|
|
|
|
|
|
def checksum(number):
|
|
"""Calculate the checksum."""
|
|
weights = (3, 7, 1, 3, 7, 1, 3, 7, 1)
|
|
return sum(w * int(n) for w, n in zip(weights, number)) % 10
|
|
|
|
|
|
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 number.isdigit():
|
|
raise InvalidFormat()
|
|
if len(number) != 9:
|
|
raise InvalidLength()
|
|
if checksum(number) != 0:
|
|
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
|