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| author | Arthur de Jong <arthur@arthurdejong.org> | 2011-09-20 23:14:48 +0200 |
|---|---|---|
| committer | Arthur de Jong <arthur@arthurdejong.org> | 2011-09-20 23:14:48 +0200 |
| commit | 4e8d7e4bcb0eeb49f6df38b530eb39c6cf953874 (patch) | |
| tree | e71c3060b151c7822f4b2708bafdad493f763442 /stdnum/isbn.py | |
| parent | d6f9ba25c25e59099211016517c7a4a216ff13c6 (diff) | |
implement a conversion function from ISBN13 to ISBN10
git-svn-id: http://arthurdejong.org/svn/python-stdnum/python-stdnum@80 9dea7c4f-944c-4273-ac1a-574ede026edc
Diffstat (limited to 'stdnum/isbn.py')
| -rw-r--r-- | stdnum/isbn.py | 24 |
1 files changed, 24 insertions, 0 deletions
diff --git a/stdnum/isbn.py b/stdnum/isbn.py index 382b13d..59262ba 100644 --- a/stdnum/isbn.py +++ b/stdnum/isbn.py @@ -37,6 +37,8 @@ False 'ISBN13' >>> to_isbn13('1-85798-218-5') '978-1-85798-218-3' +>>> to_isbn10('978-1-85798-218-3') +'1-85798-218-5' """ from stdnum import ean @@ -111,6 +113,28 @@ def to_isbn13(number): return '978' + number +def to_isbn10(number): + """Convert the number to ISBN-13 format.""" + number = number.strip() + min_number = compact(number) + if len(min_number) == 10: + return number # nothing to do, already ISBN-13 + elif isbn_type(min_number) != 'ISBN13': + raise ValueError('Not a valid ISBN13.') + elif not number.startswith('978'): + raise ValueError('Does not use 978 Bookland prefix.') + # strip EAN prefix + number = number[3:-1].strip().strip('-') + digit = _calc_isbn10_check_digit(min_number[3:-1]) + # append the new check digit + if ' ' in number: + return number + ' ' + digit + elif '-' in number: + return number + '-' + digit + else: + return number + digit + + def split(number, convert=False): """Split the specified ISBN into an EAN.UCC prefix, a group prefix, a registrant, an item number and a check-digit. If the number is in ISBN-10 |