numpy.hstack() in Python

numpy.hstack() function is used to stack the sequence of input arrays horizontally (i.e. column wise) to make a single array.

Syntax : numpy.hstack(tup)

Parameters :
tup : [sequence of ndarrays] Tuple containing arrays to be stacked. The arrays must have the same shape along all but the second axis.

Return : [stacked ndarray] The stacked array of the input arrays.

Code #1 :

# Python program explaining
# hstack() function

import numpy as geek

# input array
in_arr1 = geek.array([ 1, 2, 3] )
print ("1st Input array : \n", in_arr1)

in_arr2 = geek.array([ 4, 5, 6] )
print ("2nd Input array : \n", in_arr2)

# Stacking the two arrays horizontally
out_arr = geek.hstack((in_arr1, in_arr2))
print ("Output horizontally stacked array:\n ", out_arr)

Output:

1st Input array : 
 [1 2 3]
2nd Input array : 
 [4 5 6]
Output horizontally stacked array:
  [1 2 3 4 5 6]

Code #2 :

# Python program explaining
# hstack() function

import numpy as geek

# input array
in_arr1 = geek.array([[ 1, 2, 3], [ -1, -2, -3]] )
print ("1st Input array : \n", in_arr1)

in_arr2 = geek.array([[ 4, 5, 6], [ -4, -5, -6]] )
print ("2nd Input array : \n", in_arr2)

# Stacking the two arrays horizontally
out_arr = geek.hstack((in_arr1, in_arr2))
print ("Output stacked array :\n ", out_arr)

Output:

1st Input array : 
 [[ 1  2  3]
 [-1 -2 -3]]
2nd Input array : 
 [[ 4  5  6]
 [-4 -5 -6]]
Output stacked array :
  [[ 1  2  3  4  5  6]
 [-1 -2 -3 -4 -5 -6]]