class Game:
    def __init__(self, name):
        self.name = name
        self.callbacks = []

    def start(self):
        for callback in self.callbacks:
            callback(self.name)


class Statistic:
    startsCount = 0
    lastGame = ""

    def game_started(self, game_name):
        self.lastGame = game_name
        self.startsCount += 1


statistic = Statistic()
heroes = Game("Heroes")
doom = Game("Doom")

# subscribe to events
heroes.callbacks.append(statistic.game_started)
doom.callbacks.append(statistic.game_started)

doom.start()
heroes.start()
# statistic.lastGame is "Heroes"
# statistic.startsCount is 2

print(statistic.lastGame)
print(statistic.startsCount)