def calculate_checksum(self):
sum_ = sum(int(x) * int(y) for x, y in enumerate(self.pzn, start=2))
checksum = sum_ % 11
if checksum == 10:
raise BarcodeError("Checksum can not be 10 for PZN.")
else:
return checksum
def __init__(self, isbn, writer=None):
isbn = isbn.replace("-", "")
self.isbn13 = isbn
if isbn[:3] not in ("978", "979"):
raise WrongCountryCodeError("ISBN must start with 978 or 979.")
if isbn[:3] == "979":
if isbn[3:5] not in ("10", "11"):
raise BarcodeError("ISBN must start with 97910 or 97911.")
EuropeanArticleNumber13.__init__(self, isbn, writer)
def __init__(self, isbn, writer=None):
isbn = isbn.replace('-', '')
self.isbn13 = isbn
if isbn[:3] not in ('978', '979'):
raise WrongCountryCodeError('ISBN must start with 978 or 979.')
if isbn[:3] == '979':
if isbn[3:5] not in ('10', '11'):
raise BarcodeError('ISBN must start with 97910 or 97911.')
EuropeanArticleNumber13.__init__(self, isbn, writer)