def __parse_book_to_po(self, book):
#把Book转化为两个PO实体
#steop1 : book->goods
goods = GoodsPO()
goods.isbn = book.isbn
goods.instant_price = book.instant_price
goods.link = book.link
goods.platform = book.platform
goods.crawling_time = book.crawling_time
#step2 : book->bookpo
bookpo = BookPO()
bookpo.description = book.description
bookpo.author = book.author
bookpo.isbn = book.isbn
bookpo.press = book.press
bookpo.title = book.title
bookpo.price = book.price
bookpo.cover = book.cover
return (goods, bookpo)
