将其他数组中的numpy数组合并为不同的numpy数组

Question

我正在研究numpy来管理不同的数组。我有一个python函数返回给我这个数组的数组:

res = [[[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]]]

我想从这个res变量中提取的是这个:

a = [1 2 1 2 1 2 1 2 1 2]
b = [5 6 5 6 5 6 5 6 5 6]
c = [7 8 7 8 7 8 7 8 7 8]

思路是提取并合并每个数组的第一个数组到a，第二个数组到b，依此类推。

你能帮我实现这个结果吗?非常感谢!

Answer 1

您可以使用numpy.hstack然后使用元组解包。

In [7]: a, b, c = np.hstack(res)                                                
In [8]: a                                                                       
Out[8]: array([1, 2, 1, 2, 1, 2, 1, 2, 1, 2])
In [9]: b                                                                       
Out[9]: array([5, 6, 5, 6, 5, 6, 5, 6, 5, 6])
In [10]: c                                                                      
Out[10]: array([7, 8, 7, 8, 7, 8, 7, 8, 7, 8])

Answer 2

给定:

import numpy as np
res = np.array([[[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]], [[1, 2], [5, 6], [7, 8]]])
a = res[:, 0]
b = res[:, 1]
c = res[:, 2]
print(a)
print(b)
print(c)

输出:

[[1 2]
[1 2]
[1 2]
[1 2]
[1 2]]
[[5 6]
[5 6]
[5 6]
[5 6]
[5 6]]
[[7 8]
[7 8]
[7 8]
[7 8]
[7 8]]

或:

print(a.flatten())
print(b.flatten())
print(c.flatten())

输出:

[1 2 1 2 1 2 1 2 1 2]
[5 6 5 6 5 6 5 6 5 6]
[7 8 7 8 7 8 7 8 7 8]