NumPy: Create random set of rows from 2D array

Last update on March 24 2025 13:39:09 (UTC/GMT +8 hours)

Generate Random Rows from 2D Array

Write a NumPy program to create a random set of rows from a 2D array.

Sample Solution:

Python Code:

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

# Creating a new 2D NumPy array 'new_array' with random integers between 0 and 4 inclusive
new_array = np.random.randint(5, size=(5, 3))

# Printing a message indicating a random set of rows from the 2D array will be displayed
print("Random set of rows from 2D array array:")

# Printing the generated 2D NumPy array 'new_array'
print(new_array) 

Sample Output:

Random set of rows from 2D array array:
[[4 0 2]
 [4 2 4]
 [1 0 4]
 [4 4 3]
 [3 4 3]]

Explanation:

In the above code –

np.random.randint(5, size=(5, 3)): Generate an array of random integers between 0 (inclusive) and 5 (exclusive). The size parameter is set to (5, 3), which specifies the shape of the resulting array, i.e., 5 rows and 3 columns. Store the generated array to the variable 'new_array'.

print(new_array): Print the resulting 'new_array'.

Pictorial Presentation:

For more Practice: Solve these Related Problems:

• Write a NumPy program to randomly select a specified number of rows from a 2D array using np.random.choice.
• Create a function that shuffles the rows of a matrix and returns a random subset of rows.
• Test the random row selection on a large array to ensure no row is repeated unless intended.
• Implement a solution that allows specifying a seed for reproducible random row generation.

Python-Numpy Code Editor: