Read/Write binary file

[Larz60+]

for 2d array, I'd use something like below

But you have a single dimension array, so you're way ahead of me on this.

import numpy as np
from scipy.ndimage.interpolation import rotate
import os

# make sure file can be found in script directory
os.chdir(os.path.abspath(os.path.dirname(__file__)))

def rotate_and_save(infilename, outfilename, rotation_angle_degrees=90):    
    orig_array = np.fromfile(infilename, dtype=np.int64)
    print(f"\noriginal array\n{orig_array}")
    new_array = rotate(orig_array, angle=rotation_angle_degrees)
    print(f"\nnew array\n{new_array}")
    np.tofile(outfilename, dtype=np.int64)

def main():
    # Use any desired angle
    rotate_and_save('channel_order.bin', 'rotated_channel_order.bin', 
        rotation_angle_degrees=180)

if __name__ == '__main__':
    main(