python redis中blpop和lpop的区别

python redis中lpop()方法是获取并删除左边第一个对象。

    def lpop(self,name: str,count: Optional[int] = None,) -> Union[Awaitable[Union[str, List, None]], Union[str, List, None]]:"""Removes and returns the first elements of the list ``name``.By default, the command pops a single element from the beginning ofthe list. When provided with the optional ``count`` argument, the replywill consist of up to count elements, depending on the list's length.For more information see https://redis.io/commands/lpop"""

 python redis中blpop()方法是获取并删除左边第一个对象，并多了一个阻塞的作用(如果传入的timeout参数大于零，执行blpop()是会检查集合里面有没有对象，没有对象则进行阻塞timeout秒，如果timeout为0或者不传则无期限代码阻塞，直到有新的对象加入到集合)。

def blpop(self, keys: List, timeout: Optional[int] = 0) -> Union[Awaitable[list], list]:"""LPOP a value off of the first non-empty listnamed in the ``keys`` list.If none of the lists in ``keys`` has a value to LPOP, then blockfor ``timeout`` seconds, or until a value gets pushed on to oneof the lists.If timeout is 0, then block indefinitely.For more information see https://redis.io/commands/blpop"""

测试lpop()方法：

import redis
import timeif __name__ == "__main__":# 使用连接池来管理多个连接pool = redis.ConnectionPool(host='127.0.0.1', port=6379,password="123456", db=0)redis_client = redis.StrictRedis(connection_pool=pool)while True:#获取消息队列print("读取mq队列")task = redis_client.lpop("task")if task is not None:print("收到消息： " + str(task))#执行任务time.sleep(1)

结果每秒会获取一次：

测试blpop()方法：

import redis
import timeif __name__ == "__main__":# 使用连接池来管理多个连接pool = redis.ConnectionPool(host='127.0.0.1', port=6379,password="123456", db=0)redis_client = redis.StrictRedis(connection_pool=pool)while True:#获取消息队列print("读取mq队列")task = redis_client.blpop(_task")if task is not None:print("收到消息： " + str(task))#执行任务time.sleep(1)

结果只读取一次，然后就阻塞了：

直到有对象进入集合，才会继续执行代码。

import redisif __name__ == "__main__":# 使用连接池来管理多个连接pool = redis.ConnectionPool(host='127.0.0.1', port=6379,password="123456", db=0)redis_client = redis.StrictRedis(connection_pool=pool)# 设置键值对redis_client.rpush("task","22")