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@hornc
Last active January 13, 2023 04:53
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from baseconv import base58
from isbnlib import is_isbn13, check_digit13
def compress_isbn(isbn):
# compresses a valid checkdigit ISBN13
isbn = isbn.replace('-', '')
assert is_isbn13(isbn)
prefix = isbn[:3]
body = isbn[3:-1]
n = int(body)
if prefix == '979':
n += 10**9
return base58.encode(n)
def decompress_isbn(s):
n = int(base58.decode(s))
n += 978 * 10**9
n = str(n)
c = check_digit13(n)
return f'{n}{c}'
#!/usr/bin/env python3
from baseconv import base58
from isbnlib import is_isbn13, check_digit13
import sys
def compress_isbn(isbn):
# compresses a valid checkdigit ISBN13
isbn = isbn.replace('-', '')
assert is_isbn13(isbn)
prefix = isbn[:3]
body = isbn[3:-1]
n = int(body)
if prefix == '979':
n += 10**9
return base58.encode(n)
def decompress_isbn(s):
n = int(base58.decode(s))
n += 978 * 10**9
n = str(n)
c = check_digit13(n)
return f'{n}{c}'
if __name__ == '__main__':
with open(sys.argv[1], 'r') as f:
for line in f:
print(compress_isbn(line.strip()))
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