diff options
author | Arthur de Jong <arthur@arthurdejong.org> | 2011-06-20 22:55:58 +0200 |
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committer | Arthur de Jong <arthur@arthurdejong.org> | 2011-06-20 22:55:58 +0200 |
commit | d101acfb563b495c0a38037c683980b91fe43259 (patch) | |
tree | 31829365ea25cf0632c62d566e2f9171d40586b6 /stdnum/isbn.py | |
parent | f5747bc592f33765cbb5738f049885df6d690de3 (diff) |
use the ean module for calculating the check digit
git-svn-id: http://arthurdejong.org/svn/python-stdnum/python-stdnum@71 9dea7c4f-944c-4273-ac1a-574ede026edc
Diffstat (limited to 'stdnum/isbn.py')
-rw-r--r-- | stdnum/isbn.py | 13 |
1 files changed, 5 insertions, 8 deletions
diff --git a/stdnum/isbn.py b/stdnum/isbn.py index 7c15541..05f311c 100644 --- a/stdnum/isbn.py +++ b/stdnum/isbn.py @@ -1,4 +1,4 @@ -# __init__.py - functions for handling ISBNs +# isbn.py - functions for handling ISBNs # # Copyright (C) 2010, 2011 Arthur de Jong # @@ -39,6 +39,8 @@ False '978-1-85798-218-3' """ +from stdnum import ean + def compact(number, convert=False): """Convert the ISBN to the minimal representation. This strips the number @@ -58,11 +60,6 @@ def _calc_isbn10_check_digit(number): check = sum( (i + 1) * int(n) for i, n in enumerate(number) ) % 11 return 'X' if check == 10 else str(check) -def _calc_isbn13_check_digit(number): - """Calculate the ISBN check digit for 13-digit numbers. The number passed - should not have the check bit included.""" - return str((10 - sum( (2 * (i % 2) + 1) * int(n) for i, n in enumerate(number))) % 10) - def isbn_type(number): """Check the passed number and returns 'ISBN13', 'ISBN10' or None (for invalid) for checking the type of number passed.""" @@ -79,7 +76,7 @@ def isbn_type(number): elif len(number) == 13: if not number.isdigit(): return None - if _calc_isbn13_check_digit(number[:-1]) != number[-1]: + if ean.calc_check_digit(number[:-1]) != number[-1]: return None return 'ISBN13' else: @@ -99,7 +96,7 @@ def to_isbn13(number): if len(min_number) == 13: return number # nothing to do, already ISBN-13 # put new check digit in place - number = number[:-1] + _calc_isbn13_check_digit('978' + min_number[:-1]) + number = number[:-1] + ean.calc_check_digit('978' + min_number[:-1]) # add prefix if ' ' in number: return '978 ' + number |