Python:在元组列表中查找最小值,最大值

Question

alist = [(1,3),(2,5),(2,4),(7,5)]

我需要获取元组中每个位置的最小值.

福克斯的例子:alist的预期输出是

min_x = 1
max_x = 7

min_y = 3
max_y = 5

有什么简单的方法吗？

Answer 1

map(max, zip(*alist))

首先解压缩您的列表,然后找到每个元组位置的最大值

>>> alist = [(1,3),(2,5),(2,4),(7,5)]
>>> zip(*alist)
[(1, 2, 2, 7), (3, 5, 4, 5)]
>>> map(max, zip(*alist))
[7, 5]
>>> map(min, zip(*alist))
[1, 3]

这也适用于列表中任何长度的元组.

Answer 2

>>> from operator import itemgetter
>>> alist = [(1,3),(2,5),(2,4),(7,5)]
>>> min(alist)[0], max(alist)[0]
(1, 7)
>>> min(alist, key=itemgetter(1))[1], max(alist, key=itemgetter(1))[1]
(3, 5)