Looping (for) through some data, concatenating along the way, appending to a list in final, but dimensions don't match in python

Question

Here is the code:

#new_right_v2 = []
for i in range(rows):
    r1_p5_first_half = np.concatenate( (new_right[i,:312].reshape(1,-1), new_right[i,625:937].reshape(1,-1), new_right[i,1250:1562].reshape(1,-1), new_right[i,1875:2187].reshape(1,-1)),axis=1)
    #print(r1_p5_first_half.shape)
    r1_p5_second_half = np.concatenate( (new_right[i,313:625].reshape(1,-1), new_right[i,938:1250].reshape(1,-1), new_right[i,1563:1875].reshape(1,-1), new_right[i,2187:2499].reshape(1,-1)),axis=1)
    
    new_right_v2.append(r1_p5_first_half)
    new_right_v2.append(r1_p5_second_half)
    new_right_v2

But when I run to check dimensions:

for i in range(40):
    print(new_right_v2[i].shape)

This output comes: (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (2, 1248) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624) (4, 624)

I don't know what happens after 10th iteration. Any idea?

Answer 1

I am actually not sure what dimensions are you checking, as new_right_v2 seems to be a list

Maybe you can apply the operations matrix-wise to all rows at once?

first_half = np.concatenate(
    new_right[:,:312],
    new_right[:,625:937],
    new_right[:,1250:1562],
    new_right[:,1875:2187])
).T