Python：對列表進行排序並相應地更改另一個列表

Question

我有兩個列表：一個包含一組x點，另一個包含y點。 Python以某種方式管理混合x點，或用戶可以。我需要按照從最低到最高的順序對它們進行排序，並且移動y點以跟隨它們的x個對應點。他們在兩個單獨的名單..我該怎麼做？

Answer 1

您可以壓縮列表並對結果進行排序。排序元組時，默認情況下，應該排序第一個成員。

>>> xs = [3,2,1] 
>>> ys = [1,2,3] 
>>> points = zip(xs,ys) 
>>> points 
[(3, 1), (2, 2), (1, 3)] 
>>> sorted(points) 
[(1, 3), (2, 2), (3, 1)] 

然後再解壓它們：

>>> sorted_points = sorted(points) 
>>> new_xs = [point[0] for point in sorted_points] 
>>> new_ys = [point[1] for point in sorted_points] 
>>> new_xs 
[1, 2, 3] 
>>> new_ys 
[3, 2, 1] 

Answer 2

如果x和y的意思是一個單元（如一個點），它將使更多的意義將它們存儲爲元組而不是兩個單獨的列表。

無論如何，這裏是你應該做的：

x = [4, 2, 5, 4, 5,…] 
y = [4, 5, 2, 3, 1,…] 

zipped_list = zip(x,y) 
sorted_list = sorted(zipped_list) 

Answer 3

>>> xs = [5, 2, 1, 4, 6, 3] 
>>> ys = [1, 2, 3, 4, 5, 6] 
>>> xs, ys = zip(*sorted(zip(xs, ys))) 
>>> xs 
(1, 2, 3, 4, 5, 6) 
>>> ys 
(3, 2, 6, 4, 1, 5) 

Answer 4

>>> import numpy 

>>> sorted_index = numpy.argsort(xs) 
>>> xs = [xs[i] for i in sorted_index] 
>>> ys = [ys[i] for i in sorted_index] 

如果你能numpy.array工作

>>> xs = numpy.array([3,2,1]) 
>>> xs = numpy.array([1,2,3]) 
>>> sorted_index = numpy.argsort(xs) 
>>> xs = xs[sorted_index] 
>>> ys = ys[sorted_index]