Difference between == and is operator in Python

• Difficulty Level : Easy
• Last Updated : 04 Aug, 2021

The Equality operator (==) compares the values of both the operands and checks for value equality. Whereas the ‘is’ operator checks whether both the operands refer to the same object or not (present in the same memory location).
 

• Python3

# python3 code to

# illustrate the

# difference between

# == and is operator

# [] is an empty list

list1 = []

list2 = []

list3=list1

if (list1 == list2):

    print("True")

else:

    print("False")

if (list1 is list2):

    print("True")

else:

    print("False")

if (list1 is list3):

    print("True")

else:   

    print("False")

list3 = list3 + list2

if (list1 is list3):

    print("True")

else:   

    print("False")

Output: 

TrueFalseTrueFalse

• The output of the first if the condition is “True” as both list1 and list2 are empty lists.
• Second, if the condition shows “False” because two empty lists are at different memory locations. Hence list1 and list2 refer to different objects. We can check it with id() function in python which returns the “identity” of an object.
• The output of the third if the condition is “True” as both list1 and list3 are pointing to the same object.
• The output of the fourth if the condition is “False” because the concatenation of two lists always produces a new list.

• Python3

list1 = []

list2 = []

print(id(list1))

print(id(list2))

Output: 

139877155242696139877155253640

This shows list1 and list2 refer to different objects.