Game = dict[str, int]

RED_MAX   = 12
GREEN_MAX = 13
BLUE_MAX  = 14

def read_game(stream=sys.stdin) -> Game:
    try:
        game_string, cubes_string = stream.readline().split(':')
    except ValueError:
        return {}

    game: Game = defaultdict(int)
    game['id'] = int(game_string.split()[-1])

    for cubes in cubes_string.split(';'):
        for cube in cubes.split(','):
            count, color = cube.split()
            game[color] = max(game[color], int(count))

    return game

def read_games(stream=sys.stdin) -> Iterator[Game]:
    while game := read_game(stream):
        yield game

def is_valid_game(game: Game) -> bool:
    return all([
        game['red']   <= RED_MAX,
        game['green'] <= GREEN_MAX,
        game['blue']  <= BLUE_MAX,
    ])

def main(stream=sys.stdin) -> None:
    valid_games = filter(is_valid_game, read_games(stream))
    sum_of_ids  = sum(game['id'] for game in valid_games)
    print(sum_of_ids)

For the second part, the main parsing remainded the same. I just had to change what I did with the games I read.

def power(game: Game) -> int:
    return game['red'] * game['green'] * game['blue']

def main(stream=sys.stdin) -> None:
    sum_of_sets = sum(power(game) for game in read_games(stream))
    print(sum_of_sets)