Identity Operators

We'll cover the following

Identity operators

Name

Symbol

Syntax

Explanation

Is operator

is

val_one is val_two

Returns True for same objects

Is not operator

is not

bool_one is not True

Returns True for non-same objects

For demonstration purposes, let’s take two variables. First we’ll set var_one to [1, 2, 3] and var_two to [1, 2, 3] as well. Applying the above identity operators would give the following results:

The is operator

True if var_one is the same object as var_two; otherwise it’s False.

Expression: The list [1, 2, 3] is the same object as the other list [1, 2, 3], which is False.

The is not operator

True if var_one is not the same object as var_two; otherwise it’s False.

Expression: The list [1, 2, 3] is not the same object as the other list [1, 2, 3], which is True.

Even though the values may be the same, the object instances are different.

Code

We can put this effectively into Python code, and you can even change the variables and experiment with the code yourself! Click on the “Run” button to see the output.

var_one = [1, 2, 3]
var_two = [1, 2, 3]
result_is = var_one is var_two
print(result_is)
result_is_not = var_one is not var_two
print(result_is_not)

Same data type values can be compared among themselves, and if the values are the same, the is operator returns True as well.

bool_one = True
bool_two = False
result_is = bool_one is bool_two
print(result_is)
result_is_not = bool_one is not bool_two
print(result_is_not)
num_one = 5
num_two = 5
result_is = num_one is num_two
print(result_is)
result_is_not = num_one is not num_two
print(result_is_not)

Note: Although 1 or True as well as 0 or False essentially represent the same thing (and the == operator considers them equal), the is operator will not consider them equal since they have distinct data types.