2025-06-07 20:06:19 +02:00

70 lines
2.6 KiB
Python

from typing import Dict, List, Tuple
from .. import BaseProvider
from .isbn import ISBN10, ISBN13, MAX_LENGTH
localized = True
class Provider(BaseProvider):
"""Generates fake ISBNs.
See https://www.isbn-international.org/content/what-isbn for the
format of ISBNs.
See https://www.isbn-international.org/range_file_generation for the
list of rules pertaining to each prefix/registration group.
"""
rules: Dict[str, Dict[str, List[Tuple[str, str, int]]]] = {}
def _body(self) -> List[str]:
"""Generate the information required to create an ISBN-10 or
ISBN-13.
"""
ean: str = self.random_element(self.rules.keys())
reg_group: str = self.random_element(self.rules[ean].keys())
# Given the chosen ean/group, decide how long the
# registrant/publication string may be.
# We must allocate for the calculated check digit, so
# subtract 1
reg_pub_len: int = MAX_LENGTH - len(ean) - len(reg_group) - 1
# Generate a registrant/publication combination
reg_pub: str = self.numerify("#" * reg_pub_len)
# Use rules to separate the registrant from the publication
rules = self.rules[ean][reg_group]
registrant, publication = self._registrant_publication(reg_pub, rules)
return [ean, reg_group, registrant, publication]
@staticmethod
def _registrant_publication(reg_pub: str, rules: List[Tuple[str, str, int]]) -> Tuple[str, str]:
"""Separate the registration from the publication in a given
string.
:param reg_pub: A string of digits representing a registration
and publication.
:param rules: A list of registrant rules which designate where
to separate the values in the string.
:returns: A (registrant, publication) tuple of strings.
"""
for rule in rules:
if rule[0] <= reg_pub[:-1] <= rule[1]:
reg_len = rule[2]
break
else:
raise Exception(f"Registrant/Publication '{reg_pub}' not found in registrant rule list.")
registrant, publication = reg_pub[:reg_len], reg_pub[reg_len:]
return registrant, publication
def isbn13(self, separator: str = "-") -> str:
ean, group, registrant, publication = self._body()
isbn = ISBN13(ean, group, registrant, publication)
return isbn.format(separator)
def isbn10(self, separator: str = "-") -> str:
ean, group, registrant, publication = self._body()
isbn = ISBN10(ean, group, registrant, publication)
return isbn.format(separator)