What is the use of the "id" function in Python?

Question

Jayant Kumar · Accepted Answer

Table of Contants
Introduction
The id function in Python is a built-in function that returns the unique identifier for an object. This identifier is a constant integer that is unique for the object during its lifetime. Understanding the id function is useful for debugging, comparing object identity, and managing object references in your code.

How the id Function Works
The id function provides a unique identifier for an object, which can be used to check if two references point to the same object in memory.
Syntax:
id(object)

**object**: The object whose unique identifier you want to retrieve.

Example with Basic Data Types:
a = [1, 2, 3]
b = [1, 2, 3]
print(id(a))
print(id(b))

Output:
140364943854400
140364943854464

In this example, a and b are two different list objects with distinct identifiers, even though they contain the same values.

Key Uses of the id Function

Object Identity: Use id to determine if two references point to the same object. This is helpful for understanding object references and avoiding unexpected behavior.
Debugging: When debugging code, id can help identify and track objects, especially in cases where objects may be unintentionally modified or shared.
Comparing Objects: Compare the id values of objects to check if they are the same object or different instances with the same content.

Example for Comparing Objects:
x = [1, 2, 3]
y = x
z = [1, 2, 3]

print(id(x) == id(y))  # True, because y is the same object as x
print(id(x) == id(z))  # False, because z is a different object with the same content

Output:
True
False

In this example, x and y have the same identifier because they refer to the same object, while z has a different identifier because it is a distinct object.

Conclusion
The id function in Python provides a unique identifier for objects, aiding in understanding object identity and tracking references. By using id, you can effectively debug your code, compare objects, and manage object lifetimes in your Python applications.

What is the use of the "id" function in Python?

Table of Contants

Introduction

How the `id` Function Works

Syntax:

Example with Basic Data Types:

Key Uses of the `id` Function

Example for Comparing Objects:

Conclusion

Similar Questions