Python Operation Redis

All of the above is the direct operation of Redis in the database command line, now learning to use Python Redis package to operate Redis, I installed redis==2.10.6, not familiar with redis command line operation of Friends, please refer to:

Redis Foundation One

Redis Foundation II

Python's interaction with Redis

• Installation:

Environment: ubuntu16.04;redis-4.0.6

$ sudo pip redis

• Test

$ ipythonimport redis    # 出现版本信息，安装成功

Redis Instantiation Objects

import== redis.StrictRedis()# redis有上面两个类可以建立连接对象，用法几乎一样，推荐使用StrictRedis.= redis.StrictRedis(host=‘localhost‘,  # 默认ip为127.0.0.1                      port=6379,   # 默认端口6379                      db=0,        # 默认数据库0                      password=None# 默认没有密码

Redis Operation String Type

• Increase

print(con.set(‘num‘‘3‘))  # string类型的插入键值对,参数key，value；返回true或Falseprint(con.setex(‘name‘,3,‘xiaobai‘# 设置一个有时间的键值对,返回true或falseprint(con.setnx(‘my‘,‘hh‘))  # 设置单个不存在的键值对print(con.mset({‘my‘:‘cai‘}))  # 设置多个键值对，返回true或falseprint(con.msetnx({‘you‘:‘tan‘,‘my‘:‘wan‘# 为不存在的键设置值，如果有一个已经存在，整个会失败，返回false

• Check

print(con.get(‘num‘))       # 获取键的值，返回二进制的数据print(con.getrange(‘name‘, 0, 2))  # 获取子串，参数key、下标范围print(con.strlen(‘name‘))  # 获取值的长度print(con.exists(‘name‘)) # 是否存在这个键，针对所有的类型

• Change

Print(CON.INCR (' num '))# Value self-add operation, return calculated result valuePrint(CON.INCR (' num ',' All '))# value plus an integer operation that returns the computed result value,Print(Con.incrby (' num ',' 5 '))# value plus an integer operation that returns the computed result valuePrint(Con.incrbyfloat (' num ',' 3.5 '))# value plus a floating-point number operation that returns the computed result valuePrint(Con.incrbyfloat (' num ',' -3.5 '))# value plus a floating-point number operation that returns the computed result valuePrint(CON.DECR (' num '))# Value-decrement operation, returns the computed result valuePrint(CON.DECR (' num ',' 5 '))# value minus an integer operation, returning the computed result valuePrint(Con.append (' Boy ',' Tom '))# string concatenation, parameter key value, returns the length of the current stringPrint(Con.setrange (' name ',' 5 ',' hh '))# string substitution character, parameter is key, offset, value, returns the length of the current string

• By deleting

print(con.delete(‘my‘,‘name‘))  # 删除多个键值对，获取删除成功的数量

Redis Operations List Type

• Increase

print(con.rpush(‘list‘‘v1‘‘v2‘))  # 从列表的首部插入，参数键、值,值可多个，返回列表的长度print(con.lpush(‘list‘‘vx‘))        # 从列表的尾部插入，参数键、值,值可多个，返回列表的长度con.lset(‘list‘,0,20)                 # 在列表的下标0位置插入20

• Check

print(con.lrange(‘list‘,0,-1))  # 获取范围内的元素，返回一个列表，原来的列表不变

• By deleting

print(con.lpop(‘list‘))   # 从列表首部弹出一个元素print(con.rpop(‘list‘))  # 从列表尾部弹出一个元素print(con.blpop(‘list‘,3))  # 从列表首部弹出一个元素,在3秒内阻塞等待，默认为0秒；没有获取值返回noneprint(con.brpop(‘list‘3))  # 从列表右端弹出一个元素,在3秒内阻塞等待，默认为0秒

• Change

print(con.rpoplpush(‘list‘‘list1‘# 将list最右端的元素移到list1的最左端，返回移动的元素# 将list最右端的元素移到list1的最左端，返回移动的元素,等待时间3秒，默认0秒print(con.brpoplpush(‘list‘‘list1‘3))print(con.ltri(‘list‘2-1# 剪切列表，返回剪切后的列表，改变了原来的列表

Redis Operation Hash

• Increase

print(con.hset(‘fruit‘,‘apple‘,‘red‘# 设置单个散列键值对,参数name,key,value,返回true或falseprint(con.hmset(‘color‘, {‘blue‘:‘good‘,‘green‘:‘bad‘}))  # 对个散列键值对,返回true或falseprint(con.hsetnx(‘goods‘‘color‘‘white‘))

• By deleting

print(con.hdel(‘color‘,‘blue‘))  # 删除散列的某些键值对，至少成功一个返回true，其他返回False

• Check

Print(Con.hget (' Color ',' Green '))# Get a single value for a hashPrint(Con.hmget (' Color ',' Green ',' Blue '))# Get multiple values for a hashPrint(Con.hkeys (' Color '))# gets all the keys of the hashPrint(Con.hvals (' Color '))# gets all the values of the hashPrint(Con.hgetall (' Color '))# Get hash of all key-value pairs, return a binary-coded dictionaryPrint(Con.hexists (' Color ',' Red '))# To determine if a hash exists for a key, return True or FalsePrint(Con.hstrlen (' Color ',' Blue '))# Gets the length of the value string, returns a numberPrint(Con.hlen (' Color '))# Gets the number of key-value pairs for the hash

• Change

print(con.hincrby(‘color‘‘blue‘3# 将散列的值加一个整数，默认加1print(con.hincrbyfloat(‘color‘‘blue‘3.5))  # 加一个浮点数，默认为1.0

Redis Operations Collection

• Increase

print(con.sadd(‘name‘‘a‘‘b‘))  # 添加元素，返回添加的个数

• By deleting

print(con.srem(‘name‘,‘a‘))  # 移除元素，返回移除元素的数量print(con.spop(‘name‘))  # 随机的移除一个元素

• Change

print(con.smove(‘name‘,‘name1‘,‘bb‘# 将bb从name移到name1，如果name1不存在，创建；返回true或false

• Check

print(con.smembers(‘name‘))  # 返回集合所有的元素，以字典的形式print(con.scard(‘name‘))  # 返回集合元素的个数print(con.sismember(‘name‘,‘b‘)) # 查看元素是否在集合中，返回true或false

Other Redis functions

• Clear the current database

• Clear Current Redis

con.flushall()

• Set expiration time for keys

con.expire(‘name‘,3)  # 单位为秒

• View server time

con.time()  # 返回时间戳和当前已过去的微秒数

• See how many lifetimes the key still has

con.ttl(key) # 时间单位为秒

• See all the Keys

con.keys()  # 默认参数为‘*‘

• Write Redis on a command-line basis

con.execute_command(‘SET‘,‘my‘, ‘hhhh‘)

Pipeline

• Pipelines can cache commands, reducing the number of times clients interact with Redis-server

# 创建一个管道值= con.pipeline()pipe.get(‘name‘)pipe.set(‘name‘,‘xiao‘)# 提交pipe.execute()

Python Operation Redis