which of the following is a valid use of the in operator as it is applied to a string? in python

The in operator is used to test the membership of a value in a sequence. When applied to a string, it checks whether a substring is present in the given string or not. Here's an example:

main.py
s = "Hello, World!"
if "Hello" in s:
    print("Substring found!")
else:
    print("Substring not found!")
107 chars
6 lines

Output:

main.py
Substring found!
17 chars
2 lines

In the above example, we are checking if the substring "Hello" is present in the string s. Since it is present, the if condition is satisfied and the corresponding message is printed.