def checksum(value):
value = clean_iban(value)
value = value[4:] + value[:2] + '00'
value_digits = ''
for x in value:
if '0' <= x <= '9':
value_digits += x
elif 'A' <= x <= 'Z':
value_digits += str(ord(x) - 55)
else:
raise Exception('{} is not a valid character for IBAN.'.format(x))
return '%02d' % (98 - int(value_digits) % 97)
def __call__(self, value):
if value is not None:
value = clean_iban(value)
country_code = value[:2]
iban_checksum = value[2:4]
# Check if the country is in the known list
if country_code not in IBAN_SPECIFICATION_CONFIG:
raise ValidationError(_('The country code does not correspond to any of the know iban specifications'))
# Decoding the specific country specification
country_data = IBAN_SPECIFICATION_CONFIG[country_code]
# Checking if the iban matches the country specification
if not match(country_data.iban_regex, value):
raise ValidationError(_('The IBAN does not match the expected format for this country'))
if country_data.checksum(value) != iban_checksum:
raise ValidationError(_('The IBAN checksum is invalid.'))
def prepare_value(self, value):
if value is not None:
value = clean_iban(value)
return ' '.join(
value[i:i + self.grouping]
for i in range(0, len(value), self.grouping))
def to_python(self, value):
value = CharField.to_python(self, value)
if value is not None:
return clean_iban(value)