The id() function in Python returns a unique id for any specified object. For example:

a = [12, 42, 5, 5]
b = (1, 43, 5)
c = "Python Programming"

print(id(a))
print(id(b))
print(id(c))

The snapshot given below shows the sample output produced by the above Python program, demonstrating the id() function:

Note: Every object in Python gets assigned its own unique id when it is created. Therefore, you'll get a different ID for the same object each time you run the program.

Python id() function syntax

The syntax of the id() function in Python is:

where obj refers to an object such as a list, string, tuple, class, etc.

Python id() function example

Here is an example of the id() function in Python.

num = 100
a = 100

print(id(100))
print(id(num))
print(id(a))

All three print() statements print the same output, which looks like this:

2245638378960
2245638378960
2245638378960

This is because the id of a particular one remains constant during the lifetime of a program.

Advantages of the id() function in Python

• Python's id() function generates a unique identifier for each object, making it useful for object identification and comparison.
• It can be used to determine if two variables refer to the same object, which can be crucial in certain programming scenarios.
• By comparing an object's current identifier with its previous identifier, the id() function can determine whether an object has been modified or reassigned.

Disadvantages of the id() function in Python

• The id() function returns an integer that is meaningless to the user and may be difficult to interpret without additional context.
• The unique identifier returned by id() is implementation-dependent and may differ between Python versions or Python interpreter implementations.
• Because it must generate a unique identifier for each object, the id() function may be computationally expensive for large or complex objects.

Python Online Test

« Previous Function Next Function »