>>> from redis import Redis
>>> from lottery import Lottery
>>> client = Redis(decode_responses=True)
>>> lottery.add_player('peter')  # 添加抽奖者
>>> lottery.add_player('jack')
>>> lottery.add_player('tom')
>>> lottery.add_player('dan')
>>> lottery.player_count()       # 查看抽奖者数量
5
['dan']              # dan 中奖了！