python concatenate array code example

Example 1: numpy merge arrays

>>> a = np.array([[1, 2], [3, 4]])
>>> b = np.array([[5, 6]])
>>> np.concatenate((a, b), axis=0)
array([[1, 2],
       [3, 4],
       [5, 6]])
>>> np.concatenate((a, b.T), axis=1)
array([[1, 2, 5],
       [3, 4, 6]])

Example 2: join two numpy 2d array

import numpy as np

a = np.array([[0, 1, 3], [5, 7, 9]])
b = np.array([[0, 2, 4], [6, 8, 10]])
c = np.concatenate((a, b), axis=0)
print(c)

Output : 
[[ 0  1  3]
 [ 5  7  9]
 [ 0  2  4]
 [ 6  8 10]]

Example 3: how to combine two arrays in python

# concatenate 2 numpy arrays: row-wise
>np.concatenate((array2D_1, array2D_2))
 
array([[ 0,  1,  2],
       [ 3,  4,  5],
       [ 6,  7,  8],
       [10, 11, 12],
       [13, 14, 15],
       [16, 17, 18]])