#

import redispool = redis.ConnectionPool(host = '127.0.0.1', port=6379, db=0)#创建连接池r = redis.Redis(connection_pool = pool) # 初始化 redispipe = r.pipeline()  #初始化管道KEY = 'count'try:    pipe.watch(KEY)         # 监听库存    pipe.multi()            # 开始事务    pipe.set(KEY, 2)        # 执行操作    pipe.execute()          # 执行事务except Exception as e:    # 事务执行过程中，如果数据被修改，则抛出异常，程序可以选择重试或退出    passfinally:    pipe.reset()            # 重置管道，为重试做准备

 

import redisfrom threading import Thread# 创建连接池pool = redis.ConnectionPool(host = '127.0.0.1', port=6379, db=0)# 初始化 redisr = redis.Redis(connection_pool = pool)KEY="count"     # 库存 keyclass BaseThread(Thread):  # 封装异步多线程工具    def __init__(self, func, *args, **kwargs):        super(BaseThread, self).__init__()        self.func = func        self._args = args        self._kwargs = kwargs    def run(self):        self.func(*self._args, **self._kwargs)def sell(i):   #售卖方法    i 用户    with r.pipeline() as pipe:              # 初始化 pipe        while 1:            try:                pipe.watch(KEY)             # 监听库存                c = int(pipe.get(KEY))      # 查看当前库存                if c > 0:                   # 有库存则售卖                    pipe.multi()            # 开始事务                    c -= 1                    pipe.set(KEY, c)        # 减少库存                    pipe.execute()          # 执行事务                    # 抢购成功并结束                    print('用户 {} 抢购成功，商品剩余 {}'.format(i, c))                    break                else:                    # 库存卖完，抢购结束                    print('用户 {} 抢购停止，商品卖完'.format(i))                    break            except Exception as e:                # 抢购失败，重试                print('用户 {} 抢购失败，重试一次'.format(i))                continue            finally:                # 重置 pipe，准备下次抢购                pipe.reset()if __name__ == "__main__":    r.set(KEY, 10)                  # 初始化 10 个库存    for i in range(15):             # 共 15 个人开始抢购        t = BaseThread(sell, i)        t.start()