def to_league_name(league_name):
    """Maps league name to the league name used by Understat for ease of use.
    """

    league_mapper = {
        "epl": "EPL",
        "la_liga": "La_liga",
        "bundesliga": "Bundesliga",
        "serie_a": "Serie_A",
        "ligue_1": "Ligue_1",
        "rfpl": "RFPL"
    }
    try:
        return league_mapper[league_name]
    except KeyError:
        return league_name