def find_exact_match(row, groups, match_cols):
    """Find an exact mach for a row in groups based on match_cols.
    """
    index = tuple(row[t] for t in match_cols)
    try:
        group = groups.get_group(index)
    except KeyError:
        return []
    clus = list(set(group.hotel_cluster))
    return clus