from functools import reduce


def _unique_from_end(in_str):
    """Return a string with all redundant characters removed,
    removing left-most redundant entries

    i.e. "ijikik" -> "jik"

    Parameters
    ----------
    in_str: str

    Returns
    -------
    str

    Examples
    --------
    >>> _unique_from_end("ijikik")
    "jik"
    """

    return reduce(lambda acc, x: acc + x if x not in acc else acc, in_str[::-1], "")[
        ::-1
    ]