（Python）按命名元组中最后一个元素的递减顺序排序

Question

我正在尝试按命名元组的最后一个“元素”以递减顺序（从最大到最小）对命名元组列表进行排序。这是我要排序的命名元组列表的 sn-p：

>>> a =[]
>>> a += [p]
>>> a
[Point(x=11, y=22)]
>>> total = []
>>> b = Point(1,33)
>>> b
Point(x=1, y=33)
>>> c = Point(99, 2)
>>> total += [b] + [c] + [p]
>>> total
[Point(x=1, y=33), Point(x=99, y=2), Point(x=11, y=22)]
>>> sorted(total, key = lambda x: x[y], reverse = True)
Traceback (most recent call last):
  File "<pyshell#26>", line 1, in <module>
    sorted(total, key = lambda x: x[y], reverse = True)
  File "<pyshell#26>", line 1, in <lambda>
    sorted(total, key = lambda x: x[y], reverse = True)
NameError: name 'y' is not defined
>>> sorted(total, key = lambda x: x['y'], reverse = True)
Traceback (most recent call last):
  File "<pyshell#27>", line 1, in <module>
    sorted(total, key = lambda x: x['y'], reverse = True)
  File "<pyshell#27>", line 1, in <lambda>
    sorted(total, key = lambda x: x['y'], reverse = True)
TypeError: tuple indices must be integers or slices, not str

但是，我不断收到上述错误。有没有办法为此类命名元组实例执行此操作？

作为粗略的指南，命名元组的列表是total，我正在尝试将元组从最大的y 排序到最小的y。所以结果应该是这样的：

>>> total
[Point(x=1, y=33), Point(x=11, y=22), Point(x=99, y=2)]

namedtuple 的文档位于：https://docs.python.org/3/library/collections.html#collections.namedtuple。

感谢您的帮助，我们将不胜感激！

Answer 1

您正在寻找以下内容：

sorted(total, key = lambda x: x.y, reverse = True)