def validate(number, strip_check_digits=False, add_check_digits=False):
"""Check if the number provided is a valid ISAN. If check digits are
present in the number they are validated. If strip_check_digits is True
any existing check digits will be removed (after checking). If
add_check_digits is True the check digit will be added if they are not
present yet."""
(root, episode, check1, version, check2) = split(number)
# check digits used
for x in root + episode + version:
if x not in '0123456789ABCDEF':
raise InvalidFormat()
# check length of all components
if len(root) != 12 or len(episode) != 4 or len(check1) not in (0, 1) or \
len(version) not in (0, 8) or len(check1) not in (0, 1):
raise InvalidLength()
# allow removing check digits
if strip_check_digits:
check1 = check2 = ''
# check check digits
if check1:
mod_37_36.validate(root + episode + check1)
if check2:
mod_37_36.validate(root + episode + version + check2)
# add check digits
if add_check_digits and not check1:
check1 = mod_37_36.calc_check_digit(root + episode)
if add_check_digits and not check2 and version:
check2 = mod_37_36.calc_check_digit(root + episode + version)
return root + episode + check1 + version + check2
def validate(number, strip_check_digits=False, add_check_digits=False):
"""Checks to see if the number provided is a valid ISAN. If check digits
are present in the number they are validated. If strip_check_digits is
True any existing check digits will be removed (after checking). If
add_check_digits is True the check digit will be added if they are not
present yet."""
(root, episode, check1, version, check2) = split(number)
# check digits used
for x in root + episode + version:
if x not in '0123456789ABCDEF':
raise InvalidFormat()
# check length of all components
if len(root) != 12 or len(episode) != 4 or len(check1) not in (0, 1) or \
len(version) not in (0, 8) or len(check1) not in (0, 1):
raise InvalidLength()
# check check digits
if check1:
mod_37_36.validate(root + episode + check1)
if check2:
mod_37_36.validate(root + episode + version + check2)
# remove or add check digits
if strip_check_digits:
check1 = check2 = ''
if add_check_digits and not check1:
check1 = mod_37_36.calc_check_digit(root + episode)
if add_check_digits and not check2 and version:
check2 = mod_37_36.calc_check_digit(root + episode + version)
return root + episode + check1 + version + check2
def validate(number):
"""Check if the number is a valid GRid."""
from stdnum.iso7064 import mod_37_36
number = compact(number)
if len(number) != 18:
raise InvalidLength()
return mod_37_36.validate(number)
def test_mod37_36(self):
sequence = self.get_sequence("ISO7064_37_36")
self.assertTrue(mod_37_36.validate(sequence.next_by_id()))
