sorting.py

import numpy as np
a1=np.array([[20,40,30],[4,6,2],[5,10,15]])
#Soritng along last axis by default - rows
a1.sort()
print (a1)
#Output:
[[20 30 40]
 [ 2  4  6]
 [ 5 10 15]]

a2=np.array([[20,40,30],[4,6,2],[5,10,15]])
#Sorting by columns - first axis
a2.sort(axis=0)
print (a2)
#Output:
[[ 4  6  2]
 [ 5 10 15]
 [20 40 30]]

#Flatten the array and sort it
a3=np.array([[20,40,30],[4,6,2],[5,10,15]])
print (np.sort(a3,axis=None))
#Output:[ 2  4  5  6 10 15 20 30 40]