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_twoprint(result_is)result_is_not = var_one is not var_twoprint(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 = Truebool_two = Falseresult_is = bool_one is bool_twoprint(result_is)result_is_not = bool_one is not bool_twoprint(result_is_not)num_one = 5num_two = 5result_is = num_one is num_twoprint(result_is)result_is_not = num_one is not num_twoprint(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.