Python: moving all elements greater than 0 to left and right in numpy array

Question

If I have an numpy array like the one below, how can I right justify or left justify the elements tat are greater than zero

[[ 0.  5.  0.  2.]
 [ 0.  0.  3.         


        

Answer 1

import numpy as np

array = [ 
          [ 0.,  5.,  0.,  2.],
          [ 0.,  0.,  3.,  2.],
          [ 0.,  0.,  0.,  0.],
          [ 2.,  0.,  0.,  1.]
        ]


def move(array, right = True):
  temp = []
  for x in array:
    x = np.array(x)
    #check positive arrays
    if len(np.where(x == 0)[0]) != len(x):
      if right:
        # little faster, compare to [::-1]
        # nonzero on right
        temp.append(x[np.argsort(-x)])
      else:
        # nonzero on left
        temp.append(np.sort(x))
    else:
        # no interchange needed
        temp.append(x)
  return temp

print (move(array, 1))

[array([ 5.,  2.,  0.,  0.]), array([ 3.,  2.,  0.,  0.]), array([ 0.,  0.,  0.,  0.]), array([ 2.,  1.,  0.,  0.])]

print (move(array, 0))

[array([ 0.,  0.,  2.,  5.]), array([ 0.,  0.,  2.,  3.]), array([ 0.,  0.,  0.,  0.]), array([ 0.,  0.,  1.,  2.])]

print (np.concatenate(list(zip(move(array, 1))), axis=0))

[[ 5.  2.  0.  0.]
 [ 3.  2.  0.  0.]
 [ 0.  0.  0.  0.]
 [ 2.  1.  0.  0.]]