def get_league_entries_by_summoner(summoner_ids):
    # Can only have 10 summoners max if it's a list
    if isinstance(summoner_ids, list) and len(summoner_ids) > 10:
        raise ValueError("Can only get leagues for up to 10 summoners at once.")

    id_string = ",".join(str(x) for x in summoner_ids) if isinstance(summoner_ids, list) else str(summoner_ids)

    # Get JSON response
    request = "{version}/league/by-summoner/{ids}/entry".format(version=cassiopeia.dto.requests.api_versions["league"], ids=id_string)
    response = cassiopeia.dto.requests.get(request)

    # Convert response to Dto type
    for id_, leagues in response.items():
        for i, league in enumerate(leagues):
            leagues[i] = cassiopeia.type.dto.league.League(league)

    return response
https://developer.riotgames.com/api/methods#!/985/3356
dataset/ETHPy150Open meraki-analytics/cassiopeia/cassiopeia/dto/leagueapi.py/get_league_entries_by_summoner