python学习笔记4-redis multi watch实现锁库存

if __name__ == "__main__":
    with sms_redis.pipeline() as pipe:
        while 1:
            try:
                # 事务开始
                pipe.multi()
                count = int(sms_redis.get(‘stock_count‘))
                if count > 0:  # 有库存
                    pipe.set(‘stock_count‘, count - 1)
                # 事务结束
                pipe.execute()
                # 把命令推送过去
                break
            except Exception:
                traceback.print_exc()
                continue

if __name__ == "__main__":
    with sms_redis.pipeline() as pipe:
        while 1:
            try:
                #关注一个key
                pipe.watch(‘stock_count’)
                count = int(pipe.get(‘stock_count‘))
                if count > 0:  # 有库存
                    # 事务开始
                    pipe.multi()
                    pipe.set(‘stock_count‘, count - 1)
                    # 事务结束
                    pipe.execute()
                    # 把命令推送过去
                break
            except Exception:
                traceback.print_exc()
                continue