Forming an array with elements in specific positions from multiple arrays in Python-CodePudding

I have an array A. I want to take the first, second,...,ninth elements of each A[0],A[1],A[2] to form a new array B. I present the current and expected outputs.

import numpy as np

A=np.array([np.array([[1, 2, 3],
              [4, 5, 6 ],
              [7, 8, 9]]),
       np.array([[[10, 11, 12],
               [13, 14, 15 ],
               [16, 17, 18]]]),
       np.array([[[19, 20, 21],
               [22, 23, 24],
               [25, 26, 27]]])], dtype=object)

for t in range(0,len(A)):
    B=A[0][t][0]
    print([B])

The current output is

[1]
[4]
[7]

The expected output is

array([[1,10,19],
        [2,11,20],
        [3,12,21],
        [4,13,22],
        [5,14,23],
        [6,15,24],
        [7,16,25],
        [8,17,26],
        [9,18,27]])

CodePudding user response：

You can traverse the array, append all values as columns and transpose the resulting matrix:

import numpy as np

A=np.array([np.array([[1, 2, 3],
              [4, 5, 6 ],
              [7, 8, 9]]),
       np.array([[[10, 11, 12],
               [13, 14, 15 ],
               [16, 17, 18]]]),
       np.array([[[19, 20, 21],
               [22, 23, 24],
               [25, 26, 27]]])], dtype=object)
               
out = np.array([A[i].flatten() for i in range(len(A))]).transpose()
#out = np.array([i.flatten() for i in A]).transpose() #Second option
print(out)

Output:

[[ 1 10 19]
 [ 2 11 20]
 [ 3 12 21]
 [ 4 13 22]
 [ 5 14 23]
 [ 6 15 24]
 [ 7 16 25]
 [ 8 17 26]
 [ 9 18 27]]

CodePudding user response：

B = np.array([a.ravel() for a in A]).T

#array([[ 1, 10, 19],
#       [ 2, 11, 20],
#       [ 3, 12, 21],
#       [ 4, 13, 22],
#       [ 5, 14, 23],
#       [ 6, 15, 24],
#       [ 7, 16, 25],
#       [ 8, 17, 26],
#       [ 9, 18, 27]])