Difference between == and is operator in Python

In Python, == and is operators are both used for comparison but they serve different purposes. The == operator checks for equality of values which means it evaluates whether the values of two objects are the same. On the other hand, is operator checks for identity, meaning it determines whether two variables point to the same object in memory.

== Operator

To compare objects based on their values, Python's equality operators (==) are employed. It calls the left object's __eq__() class method which specifies the criteria for determining equality. However, these constraints are typically written so that the equality operator == returns True if two objects, have the same value and returns False if both have different value.

x = [1, 2, 3]
y = [1, 2, 3]
z = x

# Equality comparison (==)
if x == y:
    print("True")
else:
    print("False")

Explanation:

• x == y checks if both lists have the same values. Since both lists contain [1, 2, 3], the output will be True.

‘is’ Operator

Python identity operators (is, is not) are used to compare objects based on their identity. When the variables on either side of an operator point at the exact same object, the "is" operator's evaluation is true. Otherwise, it would provide us with a false assessment.

Code Example of == operator and ‘is’ Operator : 

x = [1, 2, 3]
y = [1, 2, 3]
z = x


# Case 1: Identity comparison (is)
if x is y:
    print("True")
else:
    print("False")

# Case 2: Comparing references (is)
if x is z:
    print("True")
else:
    print("False")

False
True

Explanation:

• Case 1: x is y checks if x and y refer to the same object in memory. Since x and y are two separate list objects, the output will be False.
• Case 2: x is z checks if x and z refer to the same object. Since z is assigned to x, they are the same object, and the output will be True.

Comparison: