Membership (in, not in)
With strings, the membership operator determined whether a single character is a member of a string. With lists (and tuples), we can check whether an object is a member of a list (or tuple).
Example
>>> mixup_list = ["one","two","three","four"] >>> "one" in mixup_list True >>> 'two' in mixup_list True >>> "nine" not in mixup_list True