def rotate(string, n):
    """Rotate characters in a string.
       Expects string and n (int) for number of characters to move.
    """
    pref: str = ''
    suf: str = ''

    for pos in range(len(string)):
        if n < 0:
            if (len(string) + n) <= pos:
                pref += string[pos]
            else:
                suf += string[pos]
        else:
            if n <= pos:
                pref += string[pos]
            else:
                suf += string[pos]

    return pref + suf