mirror of
https://github.com/bookwyrm-social/bookwyrm.git
synced 2024-06-11 17:59:29 +00:00
79 lines
3.3 KiB
Python
79 lines
3.3 KiB
Python
""" Use the range message from isbn-international to hyphenate ISBNs """
|
|
import os
|
|
from xml.etree import ElementTree
|
|
import requests
|
|
|
|
from bookwyrm import settings
|
|
|
|
|
|
class IsbnHyphenator:
|
|
"""Class to manage the range message xml file and use it to hyphenate ISBNs"""
|
|
|
|
__range_message_url = "https://www.isbn-international.org/export_rangemessage.xml"
|
|
__range_file_path = os.path.join(
|
|
settings.BASE_DIR, "bookwyrm", "isbn", "RangeMessage.xml"
|
|
)
|
|
__element_tree = None
|
|
|
|
def update_range_message(self):
|
|
"""Download the range message xml file and save it locally"""
|
|
response = requests.get(self.__range_message_url)
|
|
with open(self.__range_file_path, "w", encoding="utf-8") as file:
|
|
file.write(response.text)
|
|
self.__element_tree = None
|
|
|
|
def hyphenate(self, isbn_13):
|
|
"""hyphenate the given ISBN-13 number using the range message"""
|
|
if isbn_13 is None:
|
|
return None
|
|
if self.__element_tree is None:
|
|
self.__element_tree = ElementTree.parse(self.__range_file_path)
|
|
gs1_prefix = isbn_13[:3]
|
|
reg_group = self.__find_reg_group(isbn_13, gs1_prefix)
|
|
if reg_group is None:
|
|
return isbn_13 # failed to hyphenate
|
|
registrant = self.__find_registrant(isbn_13, gs1_prefix, reg_group)
|
|
if registrant is None:
|
|
return isbn_13 # failed to hyphenate
|
|
publication = isbn_13[len(gs1_prefix) + len(reg_group) + len(registrant) : -1]
|
|
check_digit = isbn_13[-1:]
|
|
return "-".join((gs1_prefix, reg_group, registrant, publication, check_digit))
|
|
|
|
def __find_reg_group(self, isbn_13, gs1_prefix):
|
|
for ean_ucc_el in self.__element_tree.find("EAN.UCCPrefixes").findall(
|
|
"EAN.UCC"
|
|
):
|
|
if ean_ucc_el.find("Prefix").text == gs1_prefix:
|
|
for rule_el in ean_ucc_el.find("Rules").findall("Rule"):
|
|
length = int(rule_el.find("Length").text)
|
|
if length == 0:
|
|
continue
|
|
reg_grp_range = [
|
|
int(x[:length]) for x in rule_el.find("Range").text.split("-")
|
|
]
|
|
reg_group = isbn_13[len(gs1_prefix) : len(gs1_prefix) + length]
|
|
if reg_grp_range[0] <= int(reg_group) <= reg_grp_range[1]:
|
|
return reg_group
|
|
return None
|
|
return None
|
|
|
|
def __find_registrant(self, isbn_13, gs1_prefix, reg_group):
|
|
from_ind = len(gs1_prefix) + len(reg_group)
|
|
for group_el in self.__element_tree.find("RegistrationGroups").findall("Group"):
|
|
if group_el.find("Prefix").text == "-".join((gs1_prefix, reg_group)):
|
|
for rule_el in group_el.find("Rules").findall("Rule"):
|
|
length = int(rule_el.find("Length").text)
|
|
if length == 0:
|
|
continue
|
|
registrant_range = [
|
|
int(x[:length]) for x in rule_el.find("Range").text.split("-")
|
|
]
|
|
registrant = isbn_13[from_ind : from_ind + length]
|
|
if registrant_range[0] <= int(registrant) <= registrant_range[1]:
|
|
return registrant
|
|
return None
|
|
return None
|
|
|
|
|
|
hyphenator_singleton = IsbnHyphenator()
|