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 format(number, separator='-', strip_check_digits=False, add_check_digits=True):
"""Reformat the passed number to the standard format. If
add_check_digits is True the check digit will be added if they are not
present yet. If both strip_check_digits and add_check_digits are True the
check digits will be recalculated."""
(root, episode, check1, version, check2) = split(number)
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)
number = [root[i:i + 4] for i in range(0, 12, 4)] + [episode]
if check1:
number.append(check1)
if version:
number.extend((version[0:4], version[4:]))
if check2:
number.append(check2)
return separator.join(number)
def format(number,
separator='-',
strip_check_digits=False,
add_check_digits=True):
"""Reformat the number to the standard presentation format. If
add_check_digits is True the check digit will be added if they are not
present yet. If both strip_check_digits and add_check_digits are True the
check digits will be recalculated."""
(root, episode, check1, version, check2) = split(number)
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)
number = [root[i:i + 4] for i in range(0, 12, 4)] + [episode]
if check1:
number.append(check1)
if version:
number.extend((version[0:4], version[4:]))
if check2:
number.append(check2)
return separator.join(number)
