NumPy: Find the number of elements of an array, length of one array element in bytes

Last update on March 24 2025 13:39:55 (UTC/GMT +8 hours)

Array Elements Count & Memory Usage

Write a NumPy program to find the number of elements in an array. It also finds the length of one array element in bytes and the total bytes consumed by the elements.

Pictorial Presentation:

Sample Solution:

Python Code:

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

# Creating an array 'x' with specified data type 'float64'
x = np.array([1, 2, 3], dtype=np.float64)

# Printing the size of the array 'x'
print("Size of the array: ", x.size)

# Printing the length of one array element in bytes
print("Length of one array element in bytes: ", x.itemsize)

# Printing the total bytes consumed by the elements of the array 'x'
print("Total bytes consumed by the elements of the array: ", x.nbytes)

Sample Output:

Size of the array:  3                                                  
Length of one array element in bytes:  8                               
Total bytes consumed by the elements of the array:  24

Explanation:

In the above code -

x = np.array([1,2,3], dtype=np.float64): Creates a NumPy array with elements 1, 2, and 3, and with the specified dtype of float64.

print("Size of the array: ", x.size): Prints the size (number of elements) of the array, which is 3 in this case.

print("Length of one array element in bytes: ", x.itemsize): Prints the length (size) of one array element in bytes, which is 8 bytes for a float64.

print("Total bytes consumed by the elements of the array: ", x.nbytes): Prints the total bytes consumed by the elements of the array, which is the size (3 elements) multiplied by the itemsize (8 bytes) = 24 bytes.

For more Practice: Solve these Related Problems:

• Calculate the total number of elements and memory consumption of an array using its nbytes attribute.
• Compare memory usage for arrays of the same shape but different dtypes.
• Write a function that converts the memory size of an array to kilobytes and megabytes.
• Verify element size by multiplying the number of elements with the itemsize and comparing to nbytes.

Python-Numpy Code Editor: