Python: Justifying NumPy array

Question

Please I am a bit new to Python and it has been nice, I could comment that python is very sexy till I needed to shift content of a 4x4 matrix which I want to u

Answer 1

Thanks to all this is what I later use

def justify(a, direction):
    mask = a>0
    justified_mask = numpy.sort(mask,0) if direction == 'up' or direction =='down' else numpy.sort(mask, 1)
    if direction == 'up':
        justified_mask = justified_mask[::-1]
    if direction =='left':
        justified_mask = justified_mask[:,::-1]
    if direction =='right':
        justified_mask = justified_mask[::-1, :]    
    out = numpy.zeros_like(a) 
    out.T[justified_mask.T] = a.T[mask.T]
    return out