filtering list using pyisbn.validate() about pyisbn HOT 3 CLOSED

Ξ Projects/alchemist git:(master) ▶ ipython
Python 2.7.3 (default, Dec 27 2012, 21:12:10) 
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In [1]: %cd ~/Projects/pyisbn/
/home/jay/Projects/pyisbn

In [2]: from tests import test_data

In [3]: isbns = test_data.TEST_BOOKS.values()

In [4]: isbns.insert(40, '123')

In [5]: import pyisbn

In [6]: filter(lambda s: not pyisbn.validate(s), isbns)
---------------------------------------------------------------------------
IsbnError                                 Traceback (most recent call last)
<ipython-input-6-1288e1dd640e> in <module>()
----> 1 filter(lambda s: not pyisbn.validate(s), isbns)

<ipython-input-6-1288e1dd640e> in <lambda>(s)
----> 1 filter(lambda s: not pyisbn.validate(s), isbns)

/home/jay/Projects/pyisbn/pyisbn/__init__.pyc in validate(isbn)
    420 
    421     """
--> 422     isbn = _isbn_cleanse(isbn)
    423     return isbn[-1].upper() == calculate_checksum(isbn[:-1])

/home/jay/Projects/pyisbn/pyisbn/__init__.pyc in _isbn_cleanse(isbn, checksum)
    337                 raise IsbnError('non-digit checksum')
    338         else:
--> 339             raise IsbnError('ISBN must be either 10 or 13 characters long')
    340     else:
    341         if len(isbn) == 8:

IsbnError: ISBN must be either 10 or 13 characters long

In [7]: