python - 从命名元组列表中选择标题的问题

Question

我想选择书名并按字母顺序制作一个新列表

Book = namedtuple('Book', 'author title genre year price instock')
             BSI = [Book('JK Rowling', 'Harry Potter', 'Fiction', 2009, 12.50, 10),
Book('Stephanie Meyer', 'Twilight', 'Fiction', 2007, 9.99, 1),
Book('Walter Isaacson', 'Steve Jobs', 'Technology', 2011, 35.00, 200),
Book('Albert Camus', 'The Stranger', 'Fiction', 1980, 15.99, 62),
Book('Shakespeare', 'Romeo and Juliet', 'Tragedy', 1597, 11.00, 13),
Book('Sake Jager', 'Language Teaching and Language Technology', 'Technology', 1998, 87.00, 27)]

对于 BSI 中的 i：打印（排序（i.title））

Answer 1

你用namedtuple得很好。

您的使用sorted不正确。您需要通过提供参数对整个集合进行排序。key

sorted(BSI,key=lambda x:x.title)
Out[39]: 
[Book(author='JK Rowling', title='Harry Potter', genre='Fiction', year=2009, price=12.5, instock=10),
 Book(author='Sake Jager', title='Language Teaching and Language Technology', genre='Technology', year=1998, price=87.0, instock=27),
 Book(author='Shakespeare', title='Romeo and Juliet', genre='Tragedy', year=1597, price=11.0, instock=13),
 Book(author='Walter Isaacson', title='Steve Jobs', genre='Technology', year=2011, price=35.0, instock=200),
 Book(author='Albert Camus', title='The Stranger', genre='Fiction', year=1980, price=15.99, instock=62),
 Book(author='Stephanie Meyer', title='Twilight', genre='Fiction', year=2007, price=9.99, instock=1)]