sorted
,list.sort
接受可选key
参数。通过一个关键功能。该函数的返回值被用于比较,而不是原始值:
>>> from collections import namedtuple
>>> hero = namedtuple('hero', ['name', 'classes', 'level'])
>>>
>>> mainList = [
... hero(name='SirGoose', classes='Fighter', level=150),
... hero(name='Conan', classes='Barbarian', level=160),
... hero(name='KingArthur', classes='Knight', level=170)
... ]
>>> sorted(mainList, key=lambda h: (h.name, h.level))
[hero(name='Conan', classes='Barbarian', level=160),
hero(name='KingArthur', classes='Knight', level=170),
hero(name='SirGoose', classes='Fighter', level=150)]
注:这里使用的键功能(lambda
)返回一个元组。元组逐个比较。如果第一项是相同的,在未来加以比较,...用operator.attrgetter
>>> ('SirGoose', 12) < ('Barbarian', 160)
False
>>> ('SirGoose', 12) < ('SirGoose', 160)
True
备选:
>>> import operator
>>> sorted(mainList, key=operator.attrgetter('name', 'level'))
[hero(name='Conan', classes='Barbarian', level=160),
hero(name='KingArthur', classes='Knight', level=170),
hero(name='SirGoose', classes='Fighter', level=150)]