Python – Identity Operators
Identity Operators are used to check if two variables point to same reference of an object in Python. The following table lists out the two Identity operators in Python.
|is||Returns True if both operands refer to same object.||x is y|
|is not||Returns True if two operands refer to different objects.||x is not y|
Two objects are said to have same reference, if they have same id value. id is a property of the object which can be accessed using Python Builtin function id().
The following tutorials cover each of the identity operators in detail.
In the following program, we shall print the ids of x and y, along with the results of is and is not operators.
x = [1, 2, 3] y = x print(x is y) # True print(x is not y) # False print(id(x)) print(id(y))Try Online
True False 2284566373000 2284566373000
We have assigned the value of x to y. Now, both x and y store the reference to same object in memory. Therefore, x is y.
# is operator x = [1, 2, 3] y = [1, 2, 3] print(x is y) # True print(x is not y) # False print(id(x)) print(id(y))Try Online
False True 1961841222280 1961841222344
Even though the list elements are same, x and y are assigned with two different list objects. Hence, the ids are different for x and y and therefore x is not y, in this case.
In this Python Tutorial, we learned how to check if two variables hold the same object or different objects using Identity Operators.