CodeSignal Solution: rotateImage

rotateImage.py

def rotateImage(a):
    w = len(a)
    h = w
    img =[0]*h
    for col in range(h):
        img_row = [0]*w
        for row in range(w):
            img_row[h-row-1] = a[row][col]
            
        img[col] = img_row
            
    return img