Using `in` and `not in` Operators

You can determine whether a character is or isn’t in a string with the in and not in operators. Like other operators, in and not in are used in expressions and connect two values: a character to look for in a string and the string where it may be found. These expressions will evaluate to a Boolean value.

>>> "a" in "apple"
True
>>> 'b' in 'apple'
False

Since the character "a" is in "apple", it evaluated to True. Likewise, since 'b' is not in 'apple', it evaluated to False.

>>> 'a' not in "apple"
False
>>> "b" not in 'apple'
True

The not in operator is the opposite of the in operator. Notice that the results are the opposite from in. Since the character 'a' is in "apple", it evaluated to False. Since "b" is not in 'apple' it evaluated to True.