NumPy: Stack 1-D arrays as row wise

Last update on August 29 2025 12:49:27 (UTC/GMT +8 hours)

Stack 1D Arrays as Rows

Write a NumPy program to stack 1-D arrays row wise.

Sample Solution:

Python Code:

# Importing the NumPy library and aliasing it as 'np'
import numpy as np

# Printing a message indicating the original arrays will be displayed
print("\nOriginal arrays:")

# Creating a NumPy array 'x' with elements 1, 2, and 3
x = np.array((1, 2, 3))

# Creating another NumPy array 'y' with elements 2, 3, and 4
y = np.array((2, 3, 4))

# Printing a message for Array-1 and displaying the contents of array 'x'
print("Array-1")
print(x)

# Printing a message for Array-2 and displaying the contents of array 'y'
print("Array-2")
print(y)

# Stacking Array-1 'x' and Array-2 'y' as rows using np.row_stack()
new_array = np.row_stack((x, y))

# Printing a message indicating the stacking of 1-D arrays as rows and displaying the resulting new array
print("\nStack 1-D arrays as rows wise:")
print(new_array)

Sample Output:

Original arrays:
Array-1
[1 2 3]
Array-2
[2 3 4]

Stack 1-D arrays as rows wise:
[[1 2 3]
 [2 3 4]]

Explanation:

In the above code -

x = np.array((1,2,3)): It creates a 1-dimensional NumPy array x with the elements 1, 2, and 3.
y = np.array((2,3,4)): It creates another 1-dimensional NumPy array y with the elements 2, 3, and 4.
new_array = np.row_stack((x, y)): It stacks the two 1-dimensional arrays x and y row-wise to form a new 2-dimensional array new_array.
Finally print() function prints the new_array.

Pictorial Presentation:

Python NumPy: Stack 1-D arrays as row wise.

For more Practice: Solve these Related Problems:

Write a NumPy program to stack 1D arrays as rows using np.vstack and verify the output shape.
Create a function that accepts multiple 1D arrays and returns a 2D array where each array is a row.
Test the row stacking on arrays and check that the sequence of elements is maintained.
Implement a solution that contrasts np.vstack with np.row_stack for stacking 1D arrays.

Go to:

PREV : Stack 1D Arrays as Columns
NEXT : Split Array Vertically

Python-Numpy Code Editor:

Have another way to solve this solution? Contribute your code (and comments) through Disqus.