The reverse() method reverses a list in place. Given letters = ["a", "b", "c", "d"], calling letters.reverse() changes it to ["d", "c", "b", "a"]. Like sort(), reverse() modifies the original and returns None.
For a new reversed list without changing the original, use slicing: reversed_letters = letters[::-1]. You can also use the reversed() function, which returns an iterator: list(reversed(letters)) creates a new reversed list.
The choice depends on whether you need the original order preserved. Note that reverse() is different from sorting in reverse. It flips the current order regardless of values.