NumPy: Test whether any of the elements of a given array is non-zero

Last update on August 28 2025 12:36:40 (UTC/GMT +8 hours)

Test Any Non-Zero

Write a NumPy program to test if any of the elements of a given array are non-zero.

This problem involves using NumPy to perform a check on the elements of an array. The task is to write a program that determines if any of the elements in a given NumPy array are non-zero. This is useful for situations where the presence of non-zero values is significant, such as checking for valid data entries or detecting activity in datasets.

Sample Solution :

Python Code :

# Importing the NumPy library with an alias 'np'
import numpy as np

# Creating a NumPy array 'x' containing elements 1, 0, 0, and 0
x = np.array([1, 0, 0, 0])

# Printing the original array 'x'
print("Original array:")
print(x)

# Checking if any element in the array 'x' is non-zero and printing the result
print("Test whether any of the elements of a given array is non-zero:")
print(np.any(x))

# Reassigning array 'x' to a new array containing all elements as zero
x = np.array([0, 0, 0, 0])

# Printing the new array 'x'
print("Original array:")
print(x)

# Checking if any element in the updated array 'x' is non-zero and printing the result
print("Test whether any of the elements of a given array is non-zero:")
print(np.any(x)) 

Output:

Original array:
[1 0 0 0]
Test whether any of the elements of a given array is non-zero:
True
Original array:
[0 0 0 0]
Test whether any of the elements of a given array is non-zero:
False                         

Explanation:

In the above code –

x = np.array([1, 0, 0, 0]): This line creates a NumPy array 'x' with the elements 1, 0, 0, and 0.

print(np.any(x)): This line uses the np.any() function to test if any elements in the array 'x' are non-zero (i.e., not equal to zero). In this case, the first element is non-zero, so the function returns True.

x = np.array([0, 0, 0, 0]): This line creates a new NumPy array 'x' with all elements equal to 0.

print(np.any(x)): This line uses the np.any() function again to test if any elements in the new array 'x' are non-zero. In this case, all elements are zero, so the function returns False.

Visual Presentation:

For more Practice: Solve these Related Problems:

• Determine if any element in a flattened array is non-zero without using np.any.
• Write a function that checks for at least one non-zero in an array of mixed types.
• Test a multi-dimensional array for any non-zero entries using array flattening and logical checks.
• Use boolean indexing to sum up non-zero elements and decide if any exist.

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• NumPy Basic Exercises Home ↩
• NumPy Exercises Home ↩

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