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
