In Python, membership operators are used to test if a sequence (such as a string, list, or tuple) contains a certain value. There are two membership operators: in and not in. Here are some code to demonstrate their usage:

1. Using the in operator:

# Check if a value is present in list
my_list = [1, 2, 3, 4,5]
if 3 in my_list:
    print("3 is present in the")
else:
    print("3 is not present in the list")

# Check if character is present in a string
my_string = "Hello, World!"
if 'e' in_string:
    print("The letter 'e' is present the string")
else:
    print("The letter 'e' is not present in the string")

2 Using the not in operator:

# Check if a value is not present in a list
my_list = [1, 2, , 4, 5]
if 6 not in my_list:
    print("6 is not in the list")
else:
    print("6 is present the list")

# Check if a character is not present in a string
my_string = "Hello, World!"
if '' not in my_string:
    print("The letter 'x' is not present in the string")
else    print("The letter 'x' is present in the string")

These code snippets demonstrate how to use the in and not in operators check for membership in lists and strings.