Membership Operators

We'll cover the following

Membership operators

Name

Symbol

Syntax

Explanation

In operator

in

val in my_list

Returns True if the element is present in the iterable

Not in operator

not in

val not in my_tuple

Returns True if the element is not present in the iterable

For demonstration purposes, let’s consider a list of numbers, numbers_list = [1,3,5,7,9], and a specific element, 5, which we’ll call target_element. Applying the membership operators would give the following results:

The in operator

Checking if 5 is present in the list gives True.

Expression: 5 in numbers_list

The not in operator

Checking if 5 is not present in the list gives False.

Expression: 10 not in numbers_list

Code

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

numbers_list = [1, 3, 5, 7, 9]
target_element = 5
is_present = target_element in numbers_list
print(is_present)
is_not_present = target_element not in numbers_list
print(is_not_present)

Note: Membership operators are usually paired with sequences like lists, tuples, strings, and sets (any iterable data type).

Let’s take a look at another piece of code—this time using strings. The following code will result in False, as Python is case sensitive and p is not considered the same as P.

word = "Python"
print('p' in word)