In this tutorial, we will learn about python id() method and its uses with examples.

Python id() Method

What is python id() method?

The id() method in python returns the unique identity number of an object. All the objects in python have a unique integer number.

These identity numbers are assigned to the object when created and remain constant for this object until the program’s execution is ended. 

The syntax of id() is:


Python id() method Parameters

id() method only takes only one parameter as an argument.

  • object – object name whose id to be returned.

Let’s check some examples of python id() methods.

Example 1: How to use the id() method in python?

print("id of integer 4 is:",id(4))

print("id of float 67.5 is:",id(67.5))

print("id of single string python is:",id("python"))


id of integer 4 is: 9784992
id of float 67.5 is: 140008364368112
id of single string python is: 140008382164528

An id will automatically assign to a variable whenever it’s declared.

Example 2: How to use id() method with python variable?

a = 87
print("id of a is:", id(a))

b = 9.7
print("id of b is:", id(b))

c = [1,2,3]
print("id of c is:", id(c))

d = {'a':1, 'b':2,'c':3}
print("id of d is:", id(d))

The output will be as follows:

id of a is: 9787648
id of b is: 140209765336528
id of c is: 140209756669504
id of d is: 140209765321152

In python, even classes and methods have their unique identity number.

Example 3: How to use id() method with python classes and methods?

class Dog:
    age = 6
    color = "Black"

dog = Dog()
print("The id of Dog class is:",id(dog))

def User_Func():
    a = 1
    b = 3
    c = a + b

my_func = User_Func()
print("This if of User_Func function is :",id(my_func))


The id of Dog class is: 139715062134816
This if of User_Func function is: 9480720

Rules of id() method 

  • id() method will always return a unique integer number of given objects.
  • Unique numbers will remain constant during its lifetime, once assing.


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