Python redis operation example analysis [connection, pipeline, publish and subscribe, etc.]

This article example tells about Python redis operation. Shared for your reference, as follows:

I. redis

redis is a key-value storage system. Similar to Memcached, it supports relatively more value types for storage, including string, list, set, zset and hash. All of these data types support push/pop, add/remove and fetch intersection and union and difference and richer operations, and all of these operations are atomic. On top of that, redis supports sorting in a variety of different ways. Like memcached, data is cached in memory for efficiency. The difference is that redis periodically writes updated data to disk or writes modification operations to an appended record file and implements master-slave synchronization on top of that.

Redis is a high-performance key-value database. The emergence of redis, to a large extent, to compensate for the memcached such key/value storage shortcomings, in some cases can play a good complementary role to the relational database. It provides Python, Ruby, Erlang, PHP client, easy to use, Redis supports master-slave synchronization. Data can be synchronized from the master server to any number of slave servers , the slave server can be associated with other slave servers of the master server . This allows Redis to perform single-tier tree replication. Slaves can write to data intentionally or unintentionally. The full implementation of the publish/subscribe mechanism makes it possible for a slave database to subscribe to a channel and receive a complete record of the master server's message releases when synchronizing the tree anywhere.

Second, python operation redis

1、Connection method

redis-py provides two classes Redis and StrictRedis for implementing Redis commands, StrictRedis is used to implement most of the official commands and use the official syntax and commands, Redis is a subclass of StrictRedis

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import redis
r = (host='192.168.0.110', port=6379,db=0)
('name', 'zhangsan')  #add
print (('name'))  # Get

2、Connection Pool

redis-py uses a connection pool to manage all connections to a redis server, avoiding the overhead of establishing and releasing connections each time. By default, each Redis instance maintains a connection pool of its own. It is possible to create a connection pool directly, and then as a parameter Redis, so that multiple Redis instances can share a connection pool.

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import redis
pool = (host='192.168.0.110', port=6379)
r = (connection_pool=pool)
('name', 'zhangsan')  #add
print (('name'))  # Get

3、Operation

Detailed redis commands

4. Piping

redis-py defaults to creating (pooling connections) and disconnecting (returning connections to the pool) one connection per request. If you want to specify multiple commands in a single request, you can use pipline to specify multiple commands in a single request, and by default, a pipline is an atomic operation.

#!/usr/bin/env python
# -*- coding:utf-8 -*-
import redis
pool = (host='192.168.0.110', port=6379)
r = (connection_pool=pool)
pipe = (transaction=True)
('name', 'zhangsan')
('name', 'lisi')
()

5. Publish and subscribe

First define a RedisHelper class, connect to Redis, define the channel as monitor, define publish and subscribe methods.

#!/usr/bin/env python
#-*- coding:utf-8 -*-
import redis
class RedisHelper(object):
  def __init__(self):
    self.__conn = (host='192.168.0.110',port=6379)#Connect to Redis
     = 'monitor' #Define the name
  def publish(self,msg):# Define release methods
    self.__conn.publish(,msg)
    return True
  def subscribe(self):#Define the subscription method
    pub = self.__conn.pubsub()
    ()
    pub.parse_response()
    return pub

publisher

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Release
from RedisHelper import RedisHelper
obj = RedisHelper()
('hello')#Release

subscriber

#!/usr/bin/env python
# -*- coding:utf-8 -*-
#Subscription
from RedisHelper import RedisHelper
obj = RedisHelper()
redis_sub = ()# Call the subscribe method
while True:
  msg= redis_sub.parse_response()
  print (msg)

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I hope that what I have said in this article will help you in Python programming.