def book_put(book_id):
response.set_header('Content-Type', 'application/json')
prefix = get_prefix(request)
bk_input = request.json
book = Book.find_one(isbn=bk_input['isbn'])
if book:
book.title = bk_input['title']
book.description = bk_input['description']
else:
response.status = 201
book = Book(bk_input['title'], bk_input['description'], bk_input['isbn'])
Book.store(book)
response.set_header('Location', prefix + '/books/' + book.isbn)
return book.to_json(prefix)
