mirror of
https://gitlab.crans.org/mediatek/med.git
synced 2024-12-25 17:42:25 +00:00
31 lines
947 B
Python
31 lines
947 B
Python
# -*- mode: python; coding: utf-8 -*-
|
|
# Copyright (C) 2017-2019 by BDE ENS Paris-Saclay
|
|
# SPDX-License-Identifier: GPL-3.0-or-later
|
|
|
|
"""
|
|
Based on https://github.com/secnot/django-isbn-field
|
|
"""
|
|
|
|
from django.core.exceptions import ValidationError
|
|
from django.utils.translation import ugettext_lazy as _
|
|
from stdnum import isbn
|
|
|
|
|
|
def isbn_validator(raw_isbn):
|
|
"""Check string is a valid ISBN number"""
|
|
isbn_to_check = raw_isbn.replace('-', '').replace(' ', '')
|
|
|
|
if not isinstance(isbn_to_check, str):
|
|
raise ValidationError(_('Invalid ISBN: Not a string'))
|
|
|
|
if len(isbn_to_check) != 10 and len(isbn_to_check) != 13:
|
|
raise ValidationError(_('Invalid ISBN: Wrong length'))
|
|
|
|
if not isbn.is_valid(isbn_to_check):
|
|
raise ValidationError(_('Invalid ISBN: Failed checksum'))
|
|
|
|
if isbn_to_check != isbn_to_check.upper():
|
|
raise ValidationError(_('Invalid ISBN: Only upper case allowed'))
|
|
|
|
return True
|