Home > Database > Redis > body text

Python operation redis instance analysis

王林
Release: 2023-05-27 19:52:39
forward
1655 people have browsed it

redis is a Key-Value database. Value supports string (string), list (list), set (set), zset (ordered set), hash (hash type) and other types.

1. Installation

pip install redis
Copy after login

2. Two ways to connect to redis

1. Method 1 regular connection to redis

import redis
r = redis(host='localhost', port=6379, db=0)
r.set('foo', 'bar')
print(r.get('foo'))
Copy after login

The output result is:

b'bar'
Copy after login
Copy after login

2. Method 2 uses connection pool

By default, each Redis instance will maintain its own connection pool. You can directly establish a connection pool and then use it as a parameter to Redis, so that multiple Redis instances can share a connection pool.

import redis
pool = redis.ConnectionPool(host='localhost', port=6379, db=0)
r = redis.Redis(connection_pool=pool)
r.set('foo', 'bar')
print(r.get('foo'))
r.close()# 记得关闭连接池
Copy after login

The output result is:

b'bar'
Copy after login
Copy after login

3. Output result modification

The result taken out by redis defaults to bytes, we can set decode_responses=TrueChange to string

import redis
r = redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set('foo', 'bar')
print(r.get('foo'))
Copy after login

The output result is:

'bar'
Copy after login
Copy after login

4. Six data types of redis

1. Usage scenarios of different data types of redis

1) String

Counter application

2) List

Operation to get the latest N data

Message queue

Delete and filter

Real-time analysis of what is happening, used for data statistics and spam prevention (combined with Set)

3) Set

Uniqe operation to obtain all data rankings for a certain period of time Heavy value

Real-time system, anti-spam system

Mutual friends, second-time friends

Using uniqueness, all independent IPs that visit the website can be counted

When recommending friends, find the intersection based on the tag. If it is greater than a certain threshold, you can recommend

4) Hashes

Store, read, and modify user attributes

5) Sorted Set

Ranking applications, take TOP N operations

Applications that need to accurately set the expiration time (timestamp as Score)

Elements with weight, such as a game User score ranking list

Processing of expired items, sorted by time

2. Examples of six different data types in redis

1) String type String

  • String in redis is stored in memory according to one name corresponding to one value. As shown in the figure:

Python operation redis instance analysis

##1.1 set Add string

set(name, value, ex=None, px=None, nx=False, xx=False)
Copy after login

Set the value in Redis, default, create if it does not exist, if it exists then modify.

Parameters:

  • ex - Expiration time (seconds)

  • px - Expiration time (milliseconds)

  • nx - If set to True, the current set operation will be executed only if name does not exist (newly created)

    # 前提redis数据库db 当中没有key='foo'
    import redis
    r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
    r.set('foo', 'bar', nx=True)
    print(r.get('foo'))
    Copy after login


    Output:

    'bar'
    Copy after login
    Copy after login



  • xx - If set to True, the current set operation will be executed (modified) only if name exists.

  • # 前提redis数据库db=3 当中没有key='foo'
    import redis
    r = redis.Redis(host='199.28.10.122', port=6389, db=3, password='test1234', decode_responses=True)
    r.set('foo', 'bar', xx=True)
    print(r.get('foo'))
    Copy after login
Output:

None
Copy after login

1.2 When setnx KEY value does not exist, add

setnx(name, value)
Copy after login

to set the value. When only name does not exist, perform the setting operation. (Added)

# 前提redis数据库db当中没有key='too'
import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.setnx('too', 'tar')
print(r.get('too'))
r.setnx('too', 'looktar')
print(r.get('too'))
Copy after login

Output:

‘tar’
‘tar’  # 因为第一个setnx已经添加了对应数据,所以执行setnx添加('too', 'looktar')是不执行的
Copy after login

1.3 setex Set expiration time in seconds

setex(name, time, value)
Copy after login

Set value

Parameters:

time - Expiration time (numeric seconds or timedelta object)

import redis
import time
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.setex('foo', 5, 'bar')
print(r.get('foo'))
print('等待5秒')
time.sleep(5)
print(r.get('foo'))
Copy after login

Running result:

bar
等待5秒
None  # 5秒之后数据过期了
Copy after login
Copy after login

1.4 psetex Set expiration time in milliseconds

psetex(name, time_ms, value)
Copy after login

Set value

Parameters:

time_ms - Expiration time (numeric milliseconds or timedelta object)

import redis
import time
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.psetex('foo', 5000, 'bar')
print(r.get('foo'))
print('等待5秒')
time.sleep(5)
print(r.get('foo'))
Copy after login

Running result:

bar
等待5秒
None  # 5秒之后数据过期了
Copy after login
Copy after login

1.5 mset batch setting

mset(*args, **kwargs)
Copy after login

Batch setting value

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.mset({'k1': 'v1', 'k2': 'v2'})
print(r.mget("k1", "k2"))   # 一次取出多个键对应的值
print(r.mget("k1"))
Copy after login

Running result:

['v1', 'v2']
['v1']
Copy after login

1.6 mget Batch acquisition

mget(keys, *args)
Copy after login

Batch setting value

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.mset({'k1': 'v1', 'k2': 'v2'})
print(r.mget("k1", "k2"))   # 一次取出多个键对应的值
# 或
print(r.mget(["k1", "k2"]))  # 一次取出多个键对应的值
print(r.mget("k1"))
Copy after login

Running result:

['v1', 'v2']
['v1', 'v2']
['v1']
Copy after login

1.7 getset sets new value And get the original value

getset(name, value)
Copy after login

Set and get the original value

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set('food', 'beef')
print(r.get('food'))
print(r.getset("food", "barbecue"))  # 设置的新值是barbecue 设置前的值是beef
print(r.get('food'))
Copy after login

Running results:

beef # 原来的值
beef # return的是原来的值
barbecue # 重新获取“food”的值
Copy after login

1.8 getrange gets the subsequence (according to bytes, non-characters)

getrange(key, start, end)
Copy after login

Get subsequence (according to bytes, non-character)

Parameters:

  • name - Redis name

  • start - starting position (bytes)

  • end - ending position (bytes)

For example: "Motherland Long live", 0-3 means "ancestor" (the

character Chinese character in Python occupies three bytes under utf-8 encoding, and occupies 3 bytes under gbk encoding Two bytes)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("cn_name", "祖国万岁") # 汉字
print(r.getrange("cn_name", 0, 2))   # 取索引号是0-2 前3位的字节 祖 切片操作 (一个汉字3个字节 1个字母一个字节 每个字节8bit)
print(r.getrange("cn_name", 0, -1))  # 取所有的字节 祖国万岁 切片操作
r.set("en_name","zuguowansui") # 字母
print(r.getrange("en_name", 0, 2))  # 取索引号是0-2 前3位的字节 zug 切片操作 (一个汉字3个字节 1个字母一个字节 每个字节8bit)
print(r.getrange("en_name", 0, -1)) # 取所有的字节 uguowansui 切片操作
Copy after login

Running results:

祖
祖国万岁
zug
zuguowansui
Copy after login

1.9 setrange modifies the string content

setrange(name, offset, value)
Copy after login

Modifies the string content and replaces backward starting from the specified string index ( When the new value is too long, it will be added backward)

Parameters:

  • offset - the index of the string, bytes (one Chinese character is three bytes)

  • value - the value to be set

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.setrange("en_name", 1, "ccc")
print(r.get("en_name"))    # zcccowansui 原始值是zuguowansui 从索引号是1开始替换成ccc
Copy after login

Running result:

zcccowansui
Copy after login

1.10 setbit bit of the binary representation of the corresponding value of name Perform operations

setbit(name, offset, value)
Copy after login
  • Operation on the bits of the binary representation of the corresponding value of name

    Parameters:

    Note: If there is a corresponding in Redis: n1 = "foo",

    那么字符串foo的二进制表示为:01100110 01101111 01101111

    所以,如果执行 setbit('n1', 7, 1),则就会将第7位设置为1,

    那么最终二进制则变成 01100111 01101111 01101111,即:"goo"


    • name - redis的name

    • offset - 位的索引(将值变换成二进制后再进行索引)

    • value - 值只能是 1 或 0

1.11 getbit 获取name对应的值的二进制表示中的某位的值 (0或1)

getbit(name, offset)
Copy after login

获取name对应的值的二进制表示中的某位的值 (0或1)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.getbit("foo1", 0)) # 0 foo1 对应的二进制 4个字节 32位 第0位是0还是1
Copy after login

1.12 bitcount获取name对应的值的二进制表示中 1 的个数

bitcount(key, start=None, end=None)
Copy after login

获取name对应的值的二进制表示中 1 的个数

参数:

  • key - Redis的name

  • start - 字节起始位置

  • end - 字节结束位置

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set('foo','baksks')
print(r.get("foo"))  # goo1 01100111
print(r.bitcount("foo",0,1))  # 11
Copy after login

运行结果:

baksks
6
Copy after login

1.13 bittop获取多个值,并将值做位运算,将最后的结果保存至新的name对应的值

bitop(operation, dest, *keys)
Copy after login

获取多个值,并将值做位运算,将最后的结果保存至新的name对应的值

参数:

  • operation - AND(并) 、 OR(或) 、 NOT(非) 、 XOR(异或)

  • dest - 新的Redis的name

  • *keys - 要查找的Redis的name

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("n1", 'goo1')
r.set("n2", 'baaanew')
r.set("n3", 'appaanew')
r.bitop("AND", 'new_name', 'n1', 'n2', 'n3')
print(r.get('new_name'))
Copy after login

运行结果:

```!
Copy after login

1.14 strlen返回name对应值的字节长度(一个汉字3个字节)

strlen(name)
Copy after login

返回name对应值的字节长度(一个汉字3个字节)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set('foo1s', 'flash')
print(r.strlen("foo1s"))
Copy after login

运行结果:

5
Copy after login

1.15 incr自增 name 对应的值,当 name 不存在时,则创建 name=amount,否则,则自增

incr(self, name, amount=1)
Copy after login

自增 name 对应的值,当 name 不存在时,则创建 name=amount,否则,则自增。

参数:

  • name - Redis的name

  • amount - 自增数(必须是整数)

注:同 incrby

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set('foo1', 'flash')
r.set('foo2', 'fla2sh')
r.set("foo", 123)
print(r.mget("foo", "foo1", "foo2", "k1", "k2"))
r.incr("foo", amount=1)
print(r.mget("foo", "foo1", "foo2", "k1", "k2"))
r.incr("foono", amount=1) # 不存在‘foono’
print(r.mget("foono", "foo1", "foo2", "k1", "k2"))
Copy after login

运行结果:

['123', 'flash', 'fla2sh', 'v1', 'v2']
['124', 'flash', 'fla2sh', 'v1', 'v2']
['1', 'flash', 'fla2sh', 'v1', 'v2'] # 当 name 不存在时,则创建 name=amount
Copy after login

应用场景:

假定我们对一系列页面需要记录点击次数。点击次数远远超过回帖次数,因此需要记录论坛的每个帖子的点击次数。如果使用关系数据库来存储点击,可能存在大量的行级锁争用。所以,点击数的增加使用redis的INCR命令最好不过了。

当redis服务器启动时,可以从关系数据库读入点击数的初始值(12306这个页面被访问了34634次)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("visit:12306:totals", 34634)
print(r.get("visit:12306:totals"))
r.incr("visit:12306:totals")
print(r.get("visit:12306:totals"))
Copy after login

Python operation redis instance analysis

运行结果:

34634
34635
Copy after login

1.16 incrbyfloat自增 name对应的值,当name不存在时,则创建name=amount,否则,则自增。

incrbyfloat(self, name, amount=1.0)
Copy after login

自增 name对应的值,当name不存在时,则创建name=amount,否则,则自增。

参数:

  • name - Redis的name

  • amount - 自增数(浮点型)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("foo1", "123.0")
r.set("foo2", "221.0")
print(r.mget("foo1", "foo2"))
r.incrbyfloat("foo1", amount=2.0)
r.incrbyfloat("foo2", amount=3.0)
print(r.mget("foo1", "foo2"))
Copy after login

运行结果:

['123.0', '221.0']
['125', '224']
Copy after login

1.17 decr自减 name 对应的值,当 name 不存在时,则创建 name=amount,否则,则自减。

decr(self, name, amount=1)
Copy after login

自减 name 对应的值,当 name 不存在时,则创建 name=amount,否则,则自减。

参数:

  • name - Redis的name

  • amount - 自减数(整数)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("foo1", "123")
r.set("foo4", "221")
r.decr("foo4", amount=3) # 递减3
r.decr("foo1", amount=1) # 递减1
print(r.mget("foo1", "foo4"))
Copy after login

运行结果:

['122', '218']
Copy after login

1.18 appen在 name对应的值后面追加内容

append(key, value)
Copy after login

在redis name对应的值后面追加内容

参数:

  • key - redis的name

  • value - 要追加的字符串

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.set("foo1", "123")
r.append("foo1", "haha")    # 在name对应的值junxi后面追加字符串haha
print(r.mget("foo1"))
Copy after login

运行结果:

['123haha']
Copy after login

2)hash

2.1 hset单个增加--修改(单个取出)--没有就新增,有的话就修改

hset(name, key, value)
Copy after login

name对应的hash中设置一个键值对(不存在,则创建;否则,修改)

参数:

  • name - redis的name

  • key - name对应的hash中的key

  • value - name对应的hash中的value

注:hsetnx(name, key, value) 当name对应的hash中不存在当前key时则创建(相当于添加

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hset("hash1", "k1", "v1")
r.hset("hash1", "k2", "v2")
print(r.hkeys("hash1")) # 取hash中所有的key
print(r.hget("hash1", "k1"))    # 单个取hash的key对应的值
print(r.hmget("hash1", "k1", "k2")) # 多个取hash的key对应的值
r.hsetnx("hash1", "k2", "v3") # 只能新建
print(r.hget("hash1", "k2"))
Copy after login

运行结果:

['k1', 'k2']
v1
['v1', 'v2']
v2 # 这里因为存在所以原值没有被修改,没有新增
Copy after login

2.2 hmset在name对应的hash中批量设置键值对

hmset(name, mapping)
Copy after login

在name对应的hash中批量设置键值对

参数:

  • name - redis的name

  • mapping - 字典,如:{'k1':'v1', 'k2': 'v2'}

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hget("hash2", 'k2'))
Copy after login

运行结果:

v2
Copy after login

2.3 hmget在name对应的hash中获取多个key的值

hmget(name, keys, *args)
Copy after login

在name对应的hash中获取多个key的值

参数:

  • name - reids对应的name

  • keys - 要获取key集合,如:['k1', 'k2', 'k3']

  • *args - 要获取的key,如:k1,k2,k3

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hget("hash2", "k2"))  # 单个取出"hash2"的key-k2对应的value
print(r.hmget("hash2", "k2", "k3"))  # 批量取出"hash2"的key-k2 k3对应的value --方式1
print(r.hmget("hash2", ["k2", "k3"]))  # 批量取出"hash2"的key-k2 k3对应的value --方式2
Copy after login

运行结果:

v2
['v2', 'v3']
['v2', 'v3']
Copy after login

2.4 hgetall取出所有键值对

hgetall(name)
Copy after login

获取name对应hash的所有键值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hgetall("hash2"))
Copy after login

运行结果:

{'k2': 'v2', 'k3': 'v3'}
Copy after login

2.5 hlen得到所有键值对的格式 hash长度

hlen(name)
Copy after login

获取name对应的hash中键值对的个数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hlen("hash2"))
Copy after login

运行结果:

2
Copy after login

2.6 hkeys得到所有的keys(类似字典的取所有keys)

hkeys(name)
Copy after login

获取name对应的hash中所有的key的值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hkeys("hash2"))
Copy after login

运行结果:

['k2', 'k3']
Copy after login

2.7 hvals得到所有的value(类似字典的取所有value)

hvals(name)
Copy after login

获取name对应的hash中所有的key的值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hvals("hash2"))
Copy after login

运行结果:

['v2', 'v3']
Copy after login

2.8 hvals判断成员是否存在(类似字典的in)

hexists(name, key)
Copy after login

检查 name 对应的 hash 是否存在当前传入的 key

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hmset("hash2", {"k2": "v2", "k3": "v3"})
print(r.hexists("hash2", "k4"))  # False 不存在
print(r.hexists("hash2", "k2"))  # True 存在
Copy after login

运行结果:

False
True
Copy after login

2.9 hdel删除键值对

hdel(name,*keys)
Copy after login

将name对应的hash中指定key的键值对删除

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.hgetall("hash1"))
r.hset("hash1", "k2", "v222")   # 修改已有的key k2
r.hset("hash1", "k11", "v1")   # 新增键值对 k11
r.hdel("hash1", "k1")    # 删除一个键值对
print(r.hgetall("hash1"))
Copy after login

运行结果:

{'k2': 'v222', 'k11': 'v1', 'k3': 'v22332', 'k1': 'v1'}
{'k2': 'v222', 'k11': 'v1', 'k3': 'v22332'}  # k1被删除了
Copy after login

2.10 hincrby自增自减整数(将key对应的value--整数 自增1或者2,或者别的整数 负数就是自减)

hincrby(name, key, amount=1)
Copy after login

自增name对应的hash中的指定key的值,不存在则创建key=amount

参数:

  • name - redis中的name

  • key - hash对应的key

  • amount - 自增数(整数)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.hset("hash1", "k3", 123)
r.hincrby("hash1", "k3", amount=-1)
print(r.hgetall("hash1"))
r.hincrby("hash1", "k4", amount=1)  # 不存在的话,value默认就是1
print(r.hgetall("hash1"))
Copy after login

运行结果:

{'k2': 'v222', 'k11': 'v1', 'k3': '122'}
{'k2': 'v222', 'k11': 'v1', 'k3': '122', 'k4': '1'}
Copy after login

2.11 hscan取值查看--分片读取

hscan(name, cursor=0, match=None, count=None)
Copy after login

增量式迭代获取,对于数据大的数据非常有用,hscan可以实现分片的获取数据,并非一次性将数据全部获取完,从而放置内存被撑爆

参数:

  • name - redis的name

  • cursor - 游标(基于游标分批取获取数据)

  • match - 匹配指定key,默认None 表示所有的key

  • count - 每次分片最少获取个数,默认None表示采用Redis的默认分片个数

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.hgetall("hash1"))
print(r.hscan("hash1"))
Copy after login

运行结果:

{'k2': 'v222', 'k11': 'v1', 'k3': '122', 'k4': '1'}
(0, {'k2': 'v222', 'k11': 'v1', 'k3': '122', 'k4': '1'})
Copy after login

2.12 hscan_iter利用yield封装hscan创建生成器,实现分批去redis中获取数据

hscan_iter(name, match=None, count=None))
Copy after login

利用yield封装hscan创建生成器,实现分批去redis中获取数据

参数:

  • match - 匹配指定key,默认None 表示所有的key

  • count - 每次分片最少获取个数,默认None表示采用Redis的默认分片个数

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.hgetall("hash1"))
for item in r.hscan_iter('hash1'):
    print(item)
print(r.hscan_iter("hash1"))    # 生成器内存地址
Copy after login

运行结果:

{'k2': 'v222', 'k11': 'v1', 'k3': '122', 'k4': '1'}
('k2', 'v222')
('k11', 'v1')
('k3', '122')
('k4', '1')
Copy after login

3)list

3.1 lpush增加(类似于list的append,只是这里是从左边新增加)--没有就新建

lpush(name,values)
Copy after login

在name对应的list中添加元素,每个新的元素都添加到列表的最左边

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lpush("list1", 11, 22, 33)
print(r.lrange('list1', 0, -1))
Copy after login

运行结果:

['33', '22', '11']
Copy after login

3.2 rpush增加(类似于list的append,只是这里是从右边新增加)--没有就新建

rpush(name,values)
Copy after login

在name对应的list中添加元素,每个新的元素都添加到列表的最右边

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.rpush("list2", 11, 22, 33)
print(r.lrange('list2', 0, -1))
Copy after login

运行结果:

['11', '22', '33']
Copy after login

3.3 llen查询列表长度

llen(name)
Copy after login

在name对应的list中添加元素,每个新的元素都添加到列表的最右边

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.rpush("list2", 11, 22, 33)
print(r.llen("list2"))  # 列表长度
print(r.lrange('list2', 0, -1))
Copy after login

运行结果:

6
['11', '22', '33', '11', '22', '33']
Copy after login

3.4 lpushx往已经有的name的列表的左边添加元素,没有的话无法创建

lpushx(name,value)
Copy after login

在name对应的list中添加元素,只有name已经存在时,值添加到列表的最左边

更多:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lpushx("list10", 10)   # 这里list10不存在
print(r.llen("list10"))  # 0
print(r.lrange("list10", 0, -1))  # []
r.lpushx("list2", 77)   # 这里"list2"之前已经存在,往列表最左边添加一个元素,一次只能添加一个
print(r.llen("list2"))  # 列表长度
print(r.lrange("list2", 0, -1)) # 切片取出值,范围是索引号0到-1(最后一个元素
Copy after login

运行结果:

0
[]
7
['77', '11', '22', '33', '11', '22', '33']
Copy after login

3.5 rpushx往已经有的name的列表的右边添加元素,没有的话无法创建

rpushx(name,value)
Copy after login

在name对应的list中添加元素,只有name已经存在时,值添加到列表的最右边

更多:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.rpushx("list2", 99)   # 这里"foo_list1"之前已经存在,往列表最右边添加一个元素,一次只能添加一个
print(r.llen("list2"))  # 列表长度
print(r.lrange("list2", 0, -1)) # 切片取出值,范围是索引号0到-1(最后一个元素)
Copy after login

运行结果:

8
['77', '11', '22', '33', '11', '22', '33', '99']
Copy after login

3.6 linsert新增(固定索引号位置插入元素)

linsert(name, where, refvalue, value)
Copy after login

在name对应的列表的某一个值前或后插入一个新值

参数:

  • name - redis的name

  • where - BEFORE或AFTER

  • refvalue - 标杆值,即:在它前后插入数据

  • value - 要插入的数据

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.linsert("list2", "before", "11", "00")   # 往列表中左边第一个出现的元素"11"前插入元素"00"
print(r.lrange("list2", 0, -1))   # 切片取出值,范围是索引号0-最后一个元素
Copy after login

运行结果:

['77', '00', '11', '22', '33', '11', '22', '33', '99']
Copy after login

3.7 lset修改(指定索引号进行修改)

r.lset(name, index, value)
Copy after login
Copy after login

对name对应的list中的某一个索引位置重新赋值

参数:

  • name - redis的name

  • index - list的索引位置

  • value - 要设置的值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lset("list2", 0, -11)    # 把索引号是0的元素修改成-11
print(r.lrange("list2", 0, -1))
Copy after login
Copy after login

运行结果:

['-11', '00', '11', '22', '33', '11', '22', '33', '99']
Copy after login

3.8 lset修改(指定索引号进行修改)

r.lset(name, index, value)
Copy after login
Copy after login

对name对应的list中的某一个索引位置重新赋值

参数:

  • name - redis的name

  • index - list的索引位置

  • value - 要设置的值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lset("list2", 0, -11)    # 把索引号是0的元素修改成-11
print(r.lrange("list2", 0, -1))
Copy after login
Copy after login

运行结果(发现没成功,没找到原因):

['-11', '11', '-11', '00', '11', '22', '33', '11', '22', '33', '99']
Copy after login

3.9 lrem删除(指定值进行删除)

r.lrem(name, value, num)
Copy after login

在name对应的list中删除指定的值

参数:

  • name - redis的name

  • value - 要删除的值

  • num - num=0,删除列表中所有的指定值;

  • num=2 - 从前到后,删除2个, num=1,从前到后,删除左边第1个

  • num=-2 - 从后向前,删除2个

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lrem("list2", "11", 1)    # 将列表中左边第一次出现的"11"删除
print(r.lrange("list2", 0, -1))
r.lrem("list2", "99", -1)    # 将列表中右边第一次出现的"99"删除
print(r.lrange("list2", 0, -1))
r.lrem("list2", "22", 0)    # 将列表中所有的"22"删除
print(r.lrange("list2", 0, -1))
Copy after login
Copy after login

运行结果(发现没成功,没找到原因):

['-11', '11', '-11', '00', '11', '22', '33', '11', '22', '33', '99']
['-11', '11', '-11', '00', '11', '22', '33', '11', '22', '33', '99']
['-11', '11', '-11', '00', '11', '22', '33', '11', '22', '33', '99']
Copy after login

3.10 lpop删除并返回

r.lpop(name)
Copy after login

在name对应的列表的左侧获取第一个元素并在列表中移除,返回值则是第一个元素

更多:

rpop(name) 表示从右向左操作

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lrem("list2", "11", 1)    # 将列表中左边第一次出现的"11"删除
print(r.lrange("list2", 0, -1))
r.lrem("list2", "99", -1)    # 将列表中右边第一次出现的"99"删除
print(r.lrange("list2", 0, -1))
r.lrem("list2", "22", 0)    # 将列表中所有的"22"删除
print(r.lrange("list2", 0, -1))
Copy after login
Copy after login

运行结果:

['11', '-11', '00', '11', '22', '33', '11', '22', '33', '99']
['11', '-11', '00', '11', '22', '33', '11', '22', '33']
Copy after login

3.11 ltrim删除索引之外的值

ltrim(name, start, end)
Copy after login

在name对应的列表中移除没有在start-end索引之间的值

参数:

  • name - redis的name

  • start - 索引的起始位置

  • end - 索引结束位置

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.lrange("list2", 0, -1))
r.ltrim("list2", 0, 2)    # 删除索引号是0-2之外的元素,值保留索引号是0-2的元素
print(r.lrange("list2", 0, -1))
Copy after login

运行结果:

['11', '-11', '00', '11', '22', '33', '11', '22', '33']
['11', '-11', '00']
Copy after login

3.12 lindex取值(根据索引号取值)

lindex(name, index)
Copy after login

在name对应的列表中根据索引获取列表元素

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.lrange("list2", 0, -1))
print(r.lindex("list2", 0))  # 取出索引号是0的值
Copy after login

运行结果:

['11', '-11', '00']
11
Copy after login

3.13 rpoplpush移动 元素从一个列表移动到另外一个列表

rpoplpush(src, dst)
Copy after login

从一个列表取出最右边的元素,同时将其添加至另一个列表的最左边

参数:

  • src - 要取数据的列表的 name

  • dst - 要添加数据的列表的 name

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.lrange("list1", 0, -1))
print(r.lrange("list2", 0, -1))
r.rpoplpush("list1", "list2")
print(r.lrange("list2", 0, -1))
Copy after login

运行结果:

['33', '22', '11']
['11', '-11', '00']
['11', '11', '-11', '00']
Copy after login

3.14 brpoplpush移动 元素从一个列表移动到另外一个列表 可以设置超时

brpoplpush(src, dst, timeout=0)
Copy after login

从一个列表的右侧移除一个元素并将其添加到另一个列表的左侧

参数:

  • src - 取出并要移除元素的列表对应的name

  • dst - 要插入元素的列表对应的name

  • timeout - 当src对应的列表中没有数据时,阻塞等待其有数据的超时时间(秒),0 表示永远阻塞

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.lrange("list1", 0, -1))
print(r.lrange("list2", 0, -1))
r.brpoplpush("list1", "list2", timeout=2)
print(r.lrange("list2", 0, -1))
Copy after login

运行结果:

['33', '22']
['11', '11', '-11', '00']
['22', '11', '11', '-11', '00']
Copy after login

3.15 blpop一次移除多个列表

blpop(keys, timeout)
Copy after login

将多个列表排列,按照从左到右去pop对应列表的元素

参数:

  • keys - redis的name的集合

  • timeout - 超时时间,当元素所有列表的元素获取完之后,阻塞等待列表内有数据的时间(秒), 0 表示永远阻塞

更多:

r.brpop(keys, timeout) 同 blpop,将多个列表排列,按照从右像左去移除各个列表内的元素

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.lpush("list10", 3, 4, 5)
r.lpush("list11", 3, 4, 5)
while True:
    r.blpop(["list10", "list11"], timeout=2)
    print(r.lrange("list10", 0, -1), r.lrange("list11", 0, -1))
Copy after login

运行结果:

['4', '3'] ['5', '4', '3']
['3'] ['5', '4', '3']
[] ['5', '4', '3']
[] ['4', '3']
[] ['3']
[] []
[] []
[] []
[] []
[] []
[] []
[] []
[] []
[] []
Copy after login

3.16 自定义增量迭代:

由于redis类库中没有提供对列表元素的增量迭代,如果想要循环name对应的列表的所有元素,那么就需要获取name对应的所有列表。

循环列表

但是,如果列表非常大,那么就有可能在第一步时就将程序的内容撑爆,所有有必要自定义一个增量迭代的功能:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.lrange("list2", 0, -1))


def list_iter(name):
    """
    自定义redis列表增量迭代
    :param name: redis中的name,即:迭代name对应的列表
    :return: yield 返回 列表元素
    """
    list_count = r.llen(name)
    for index in range(list_count):
        yield r.lindex(name, index)

# 使用
for item in list_iter('list2'): # 遍历这个列表
    print(item)
Copy after login

运行结果:

['22', '11', '11', '-11', '00']
22
11
11
-11
00
Copy after login

4)set

4.1 sadd新增

sadd(name,values)
Copy after login

name - 对应的集合中添加元素

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.sadd("set1", 33, 44, 55, 66)  # 往集合中添加元素
print(r.scard("set1"))  # 集合的长度是4
print(r.smembers("set1"))   # 获取集合中所有的成员
Copy after login

运行结果:

4
{'66', '55', '44', '33'}
Copy after login

4.2 scard.获取元素个数 类似于len

scard(name)
Copy after login

获取name对应的集合中元素个数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.smembers("set1"))   # 获取集合中所有的成员
print(r.scard("set1"))  # 集合的长度是4
Copy after login

运行结果:

{'55', '66', '33', '44'}
4
Copy after login

4.3 smembets获取集合中所有的成员

smembers(name)
Copy after login

获取name对应的集合的所有成员

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.smembers("set1"))   # 获取集合中所有的成员
sscan(name, cursor=0, match=None, count=None)
Copy after login

运行结果:

{'55', '66', '33', '44'}
Copy after login

4.4 sscan获取集合中所有的成员--元组形式

sscan(name, cursor=0, match=None, count=None)
Copy after login

获取集合中所有的成员--元组形式

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sscan("set1"))
Copy after login
Copy after login

运行结果:

(0, ['33', '44', '55', '66'])
Copy after login

4.5 sscan_iter获取集合中所有的成员--迭代器的方式

sscan_iter(name, match=None, count=None)
Copy after login

获取集合中所有的成员--迭代器的方式

同字符串的操作,用于增量迭代分批获取元素,避免内存消耗太大

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sscan("set1"))
Copy after login
Copy after login

运行结果:

33
44
55
66
Copy after login

4.6 sdiff差集

sdiff(keys, *args)
Copy after login

在第一个name对应的集合中且不在其他name对应的集合的元素集合

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.sadd("set2", 11, 22, 33)
print(r.smembers("set1"))   # 获取集合中所有的成员
print(r.smembers("set2"))
print(r.sdiff("set1", "set2"))   # 在集合set1但是不在集合set2中
print(r.sdiff("set2", "set1"))   # 在集合set2但是不在集合set1中
Copy after login

运行结果:

{'55', '33', '66', '44'}
{'22', '33', '11'}
{'55', '66', '44'}
{'22', '11'}
Copy after login

4.6 sdiffstore差集--差集存在一个新的集合中

sdiffstore(dest, keys, *args)
Copy after login

获取第一个name对应的集合中且不在其他name对应的集合,再将其新加入到dest对应的集合中

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.sdiffstore("set3", "set1", "set2")    # 在集合set1但是不在集合set2中
print(r.smembers("set3"))
Copy after login

运行结果:

{'55', '44', '66'}
Copy after login

4.7 sinter交集

sinter(keys, *args)
Copy after login

获取多一个name对应集合的交集

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sinter("set1", "set2")) # 取2个集合的交集
Copy after login

运行结果:

{'33'}
Copy after login

4.8 sunion并集

sunion(keys, *args)
Copy after login

获取多个name对应的集合的并集

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sunion("set1", "set2")) # 取2个集合的并集
Copy after login

运行结果:

{'66', '33', '44', '11', '22', '55'}
Copy after login

4.9 sunionstore并集--并集存在一个新的集合

sunionstore(dest,keys, *args)
Copy after login

获取多一个name对应的集合的并集,并将结果保存到dest对应的集合中

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sunionstore("set3", "set1", "set2")) # 取2个集合的并集
print(r.smembers("set3"))
Copy after login

运行结果:

6
{'33', '66', '55', '22', '11', '44'}
Copy after login

4.10 sismember判断是否是集合的成员 类似in

sismember(name, value)
Copy after login

检查value是否是name对应的集合的成员,结果为True和False

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.sismember("set1", 33))  # 33是集合的成员
print(r.sismember("set1", 23))  # 23不是集合的成员
Copy after login

运行结果:

True
False
Copy after login

4.11 smove移动

smove(src, dst, value)
Copy after login

将某个成员从一个集合中移动到另外一个集合

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.smove("set1", "set2", 44)
print(r.smembers("set1"))
print(r.smembers("set2"))
Copy after login

运行结果:

{'66', '55', '33'}
{'44', '33', '22', '11'}
Copy after login

4.11 spop删除--随机删除并且返回被删除值

spop(name)
Copy after login

从集合移除一个成员,并将其返回,说明一下,集合是无序的,所有是随机删除的

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.spop("set2"))   # 这个删除的值是随机删除的,集合是无序的
print(r.smembers("set2"))
Copy after login

运行结果:

44
{'11', '22', '33'}
Copy after login

4.12 srem删除--指定值删除

srem(name, values)
Copy after login

在name对应的集合中删除某些值

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.srem("set2", 11))   # 从集合中删除指定值 11
print(r.smembers("set2"))
Copy after login

运行结果:

1
{'22', '33'}
Copy after login

5)有序set

Set操作,Set集合就是不允许重复的列表,本身是无序的。

有序集合,在集合的基础上,为每元素排序;元素的排序需要根据另外一个值来进行比较,所以,对于有序集合,每一个元素有两个值,即:值和分数,分数专门用来做排序。

5.1 新增

zadd(name, mapping, nx=False, xx=False, ch=False, incr=False)
Copy after login

在name对应的有序集合中添加元素

如:

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.zadd("zset1",  {'n1':100, 'n2':99, 'n3':87})
r.zadd("zset2", {'m1':100, 'm2':99, 'm3':87})
print(r.zcard("zset1")) # 集合长度
print(r.zcard("zset2")) # 集合长度
print(r.zrange("zset1", 0, -1))   # 获取有序集合中所有元素
print(r.zrange("zset2", 0, -1, withscores=True))   # 获取有序集合中所有元素和分数
Copy after login

运行结果:

3
3
['n3', 'n2', 'n1']
[('m3', 87.0), ('m2', 99.0), ('m1', 100.0)]
Copy after login

5.2 zcard获取有序集合元素个数 类似于len

zcard(name)
Copy after login

获取name对应的有序集合元素的数量

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zcard("zset1")) # 集合长度
Copy after login

运行结果:

3
Copy after login

5.3 zrange获取有序集合的所有元素

zrange( name, start, end, desc=False, withscores=False, score_cast_func=float)
Copy after login

按照索引范围获取name对应的有序集合的元素

参数:

  • name - redis的name

  • start - 有序集合索引起始位置(非分数)

  • end - 有序集合索引结束位置(非分数)

  • desc - 排序规则,默认按照分数从小到大排序

  • withscores - 是否获取元素的分数,默认只获取元素的值

  • score_cast_func - 对分数进行数据转换的函数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zrange("zset1", 0, 1)) # 集合长度
Copy after login

运行结果:

['n3', 'n2']
Copy after login

5.3 zrevrange从大到小排序(同zrange,集合是从大到小排序的)

zrevrange(name, start, end, withscores=False, score_cast_func=float)
Copy after login

从大到小排序(同zrange,集合是从大到小排序的)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zrevrange("zset1", 0, -1))    # 只获取元素,不显示分数
print(r.zrevrange("zset1", 0, -1, withscores=True)) # 获取有序集合中所有元素和分数,分数倒序
Copy after login

运行结果:

['n1', 'n2', 'n3']
[('n1', 100.0), ('n2', 99.0), ('n3', 87.0)]
Copy after login

5.4 zrangebyscore按照分数范围获取name对应的有序集合的元素

zrangebyscore(name, min, max, start=None, num=None, withscores=False, score_cast_func=float)
Copy after login

按照分数范围获取name对应的有序集合的元素

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
for i in range(1, 30):
   element = 'n' + str(i)
   r.zadd("zset3",  {element: i})
print(r.zrangebyscore("zset3", 15, 25)) # # 在分数是15-25之间,取出符合条件的元素
print(r.zrangebyscore("zset3", 12, 22, withscores=True))    # 在分数是12-22之间,取出符合条件的元素(带分数)
Copy after login

运行结果:

['n15', 'n16', 'n17', 'n18', 'n19', 'n20', 'n21', 'n22', 'n23', 'n24', 'n25']
[('n12', 12.0), ('n13', 13.0), ('n14', 14.0), ('n15', 15.0), ('n16', 16.0), ('n17', 17.0), ('n18', 18.0), ('n19', 19.0), ('n20', 20.0), ('n21', 21.0), ('n22', 22.0)]
Copy after login

5.5 zrevrangebyscore按照分数范围获取有序集合的元素并排序(默认从大到小排序)

zrevrangebyscore(name, max, min, start=None, num=None, withscores=False, score_cast_func=float)
Copy after login

按照分数范围获取有序集合的元素并排序(默认从大到小排序)

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zrevrangebyscore("zset3", 22, 11, withscores=True)) # 在分数是22-11之间,取出符合条件的元素 按照
Copy after login

运行结果:

[('n22', 22.0), ('n21', 21.0), ('n20', 20.0), ('n19', 19.0), ('n18', 18.0), ('n17', 17.0), ('n16', 16.0), ('n15', 15.0), ('n14', 14.0), ('n13', 13.0), ('n12', 12.0), ('n11', 11.0)]
Copy after login

5.6 zscan获取所有元素--默认按照分数顺序排序

zscan(name, cursor=0, match=None, count=None, score_cast_func=float)
Copy after login

获取所有元素--默认按照分数顺序排序

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zscan("zset3"))
Copy after login
Copy after login

运行结果:

(0, [('n1', 1.0), ('n2', 2.0), ('n3', 3.0), ('n4', 4.0), ('n5', 5.0), ('n6', 6.0), ('n7', 7.0), ('n8', 8.0), ('n9', 9.0), ('n10', 10.0), ('n11', 11.0), ('n12', 12.0), ('n13', 13.0), ('n14', 14.0), ('n15', 15.0), ('n16', 16.0), ('n17', 17.0), ('n18', 18.0), ('n19', 19.0), ('n20', 20.0), ('n21', 21.0), ('n22', 22.0), ('n23', 23.0), ('n24', 24.0), ('n25', 25.0), ('n26', 26.0), ('n27', 27.0), ('n28', 28.0), ('n29', 29.0)])
Copy after login

5.7 zscan_iter获取所有元素--迭代器

zscan_iter(name, match=None, count=None,score_cast_func=float)
Copy after login

获取所有元素--迭代器

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zscan("zset3"))
Copy after login
Copy after login

运行结果:

('n1', 1.0)
('n2', 2.0)
('n3', 3.0)
('n4', 4.0)
('n5', 5.0)
('n6', 6.0)
('n7', 7.0)
('n8', 8.0)
('n9', 9.0)
('n10', 10.0)
('n11', 11.0)
('n12', 12.0)
('n13', 13.0)
('n14', 14.0)
('n15', 15.0)
('n16', 16.0)
('n17', 17.0)
('n18', 18.0)
('n19', 19.0)
('n20', 20.0)
('n21', 21.0)
('n22', 22.0)
('n23', 23.0)
('n24', 24.0)
('n25', 25.0)
('n26', 26.0)
('n27', 27.0)
('n28', 28.0)
('n29', 29.0)
Copy after login

5.8 zcount获取name对应的有序集合中分数 在 [min,max] 之间的个数

zcount(name, min, max)
Copy after login

获取name对应的有序集合中分数 在 [min,max] 之间的个数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zrange("zset3", 0, -1, withscores=True))
print(r.zcount("zset3", 11, 22))
Copy after login

运行结果:

[('n1', 1.0), ('n2', 2.0), ('n3', 3.0), ('n4', 4.0), ('n5', 5.0), ('n6', 6.0), ('n7', 7.0), ('n8', 8.0), ('n9', 9.0), ('n10', 10.0), ('n11', 11.0), ('n12', 12.0), ('n13', 13.0), ('n14', 14.0), ('n15', 15.0), ('n16', 16.0), ('n17', 17.0), ('n18', 18.0), ('n19', 19.0), ('n20', 20.0), ('n21', 21.0), ('n22', 22.0), ('n23', 23.0), ('n24', 24.0), ('n25', 25.0), ('n26', 26.0), ('n27', 27.0), ('n28', 28.0), ('n29', 29.0)]
12
Copy after login

5.9 zincrby自增

zincrby(name, amount, value)
Copy after login

自增name对应的有序集合的 name 对应的分数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.zincrby("zset3", 2, "n2")    # 每次将n2的分数自增2
print(r.zrange("zset3", 0, -1, withscores=True))
Copy after login

运行结果:

[('n1', 1.0), ('n3', 3.0), ('n2', 4.0), ('n4', 4.0), ('n5', 5.0), ('n6', 6.0), ('n7', 7.0), ('n8', 8.0), ('n9', 9.0), ('n10', 10.0), ('n11', 11.0), ('n12', 12.0), ('n13', 13.0), ('n14', 14.0), ('n15', 15.0), ('n16', 16.0), ('n17', 17.0), ('n18', 18.0), ('n19', 19.0), ('n20', 20.0), ('n21', 21.0), ('n22', 22.0), ('n23', 23.0), ('n24', 24.0), ('n25', 25.0), ('n26', 26.0), ('n27', 27.0), ('n28', 28.0), ('n29', 29.0)]
Copy after login

5.10 zrank获取值的索引号

zrank(name, value)
Copy after login

获取某个值在 name对应的有序集合中的索引(从 0 开始)

更多:

zrevrank(name, value),从大到小排序

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zrank("zset3", "n1"))   # n1的索引号是0 这里按照分数顺序(从小到大)
print(r.zrank("zset3", "n6"))   # n6的索引号是1
print(r.zrevrank("zset3", "n1"))    # n1的索引号是29 这里安照分数倒序(从大到小)
Copy after login

运行结果:

0
5
28
Copy after login

5.11 zrem删除--指定值删除

zrem(name, values)
Copy after login

删除name对应的有序集合中值是values的成员

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.zrem("zset3", "n3")   # 删除有序集合中的元素n3 删除单个
print(r.zrange("zset3", 0, -1))
Copy after login

运行结果:

['n1', 'n2', 'n4', 'n5', 'n6', 'n7', 'n8', 'n9', 'n10', 'n11', 'n12', 'n13', 'n14', 'n15', 'n16', 'n17', 'n18', 'n19', 'n20', 'n21', 'n22', 'n23', 'n24', 'n25', 'n26', 'n27', 'n28', 'n29']
Copy after login

5.12 zremrangebyrank删除--根据排行范围删除,按照索引号来删除

zremrangebyrank(name, min, max)
Copy after login

根据排行范围删除

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.zremrangebyrank("zset3", 0, 1)  # 删除有序集合中的索引号是0, 1的元素
print(r.zrange("zset3", 0, -1))
Copy after login

运行结果:

['n4', 'n5', 'n6', 'n7', 'n8', 'n9', 'n10', 'n11', 'n12', 'n13', 'n14', 'n15', 'n16', 'n17', 'n18', 'n19', 'n20', 'n21', 'n22', 'n23', 'n24', 'n25', 'n26', 'n27', 'n28', 'n29']
Copy after login

5.13 zremrangebyscore删除--根据分数范围删除

zremrangebyscore(name, min, max)
Copy after login

根据排行范围删除--根据分数范围删除

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.zremrangebyscore("zset3", 11, 22)   # 删除有序集合中的分数是11-22的元素
print(r.zrange("zset3", 0, -1))
Copy after login

运行结果:

['n4', 'n5', 'n6', 'n7', 'n8', 'n9', 'n10', 'n23', 'n24', 'n25', 'n26', 'n27', 'n28', 'n29']
Copy after login

5.14 zscore获取值对应的分数

zscore(name, value)
Copy after login

获取name对应有序集合中 value 对应的分数

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.zscore("zset3", "n27"))   # 获取元素n27对应的分数27
Copy after login

运行结果:

27.0
Copy after login

五、其他常用操作

1.删除

delete(*names)
Copy after login

根据删除redis中的任意数据类型(string、hash、list、set、有序set)

r.delete("gender")  # 删除key为gender的键值对
Copy after login

2.检查名字是否存在

exists(name)
Copy after login

检测redis的name是否存在,存在就是True,False 不存在

print(r.exists("zset1"))
Copy after login

3.模糊匹配

keys(pattern='')
Copy after login

根据模型获取redis的name

更多:

  • KEYS * 匹配数据库中所有 key 。

  • KEYS h?llo 匹配 hello , hallo 和 hxllo 等。

  • KEYS hllo 匹配 hllo 和 heeeeello 等。

  • KEYS h[ae]llo 匹配 hello 和 hallo ,但不匹配 hillo

print(r.keys("foo*"))
Copy after login

4.设置超时时间

expire(name ,time)
Copy after login

为某个redis的某个name设置超时时间

r.lpush("list5", 11, 22)
r.expire("list5", time=3)
print(r.lrange("list5", 0, -1))
time.sleep(3)
print(r.lrange("list5", 0, -1))
Copy after login

5.重命名

rename(src, dst)
Copy after login

对redis的name重命名

r.lpush("list5", 11, 22)
r.rename("list5", "list5-1")
Copy after login

6.随机获取name

randomkey()
Copy after login

随机获取一个redis的name(不删除)

print(r.randomkey())
Copy after login

7.获取类型

type(name)
Copy after login

获取name对应值的类型

print(r.type("set1"))
print(r.type("hash2"))
Copy after login

8.查看所有元素

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.scan(cursor=0, match=None, count=None)
print(r.hscan("hash2"))
print(r.sscan("set3"))
print(r.zscan("zset2"))
print(r.getrange("foo1", 0, -1))
print(r.lrange("list2", 0, -1))
print(r.smembers("set3"))
print(r.zrange("zset3", 0, -1))
print(r.hgetall("hash1"))
Copy after login

运行结果:

(0, {'k2': 'v2', 'k3': 'v3'})
(0, ['11', '22', '33', '44', '55', '66'])
(0, [('m3', 87.0), ('m2', 99.0), ('m1', 100.0)])
123haha
['22', '11', '11', '-11', '00']
{'66', '55', '11', '44', '22', '33'}
['n4', 'n5', 'n6', 'n7', 'n8', 'n9', 'n10', 'n23', 'n24', 'n25', 'n26', 'n27', 'n28', 'n29']
{'k2': 'v222', 'k11': 'v1', 'k3': '122', 'k4': '1'}
Copy after login

9.查看所有元素--迭代器

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
r.scan_iter(match=None, count=None)
for i in r.hscan_iter("hash1"):
    print(i)
for i in r.sscan_iter("set3"):
    print(i)
for i in r.zscan_iter("zset3"):
    print(i)
Copy after login

运行结果:

('k2', 'v222')
('k11', 'v1')
('k3', '122')
('k4', '1')
11
22
33
44
55
66
('n4', 4.0)
('n5', 5.0)
('n6', 6.0)
('n7', 7.0)
('n8', 8.0)
('n9', 9.0)
('n10', 10.0)
('n23', 23.0)
('n24', 24.0)
('n25', 25.0)
('n26', 26.0)
('n27', 27.0)
('n28', 28.0)
('n29', 29.0)
Copy after login

六、other方法

import redis
r = redis.Redis(host='localhost', port=6379, db=0, decode_responses=True)
print(r.get('name'))    # 查询key为name的值
r.delete("gender")  # 删除key为gender的键值对
print(r.keys()) # 查询所有的Key
print(r.dbsize())   # 当前redis包含多少条数据
r.save()    # 执行"检查点"操作,将数据写回磁盘。保存时阻塞
# r.flushdb()        # 清空r中的所有数据
Copy after login

运行结果:

None
['set2', 'k2', 'food', 'visit:12306:totals', 'foo', 'foono', 'set3', 'list2', 'cn_name', 'foo2', 'n3', 'foo1', 'new_name', 'too', 'zset1', 'list1', 'set1', 'hash1', 'zset2', 'n1', 'hash2', 'foo4', 'n2', 'en_name', 'k1', 'zset3', 'foo1s']
27
Copy after login

七、管道(pipeline)

redis默认在执行每次请求都会创建(连接池申请连接)和断开(归还连接池)一次连接操作,如果想要在一次请求中指定多个命令,则可以使用pipline实现一次请求指定多个命令,并且默认情况下一次pipline 是原子性操作。

管道(pipeline)是redis在提供单个请求中缓冲多条服务器命令的基类的子类。它通过减少服务器-客户端之间反复的TCP数据库包,从而大大提高了执行批量命令的功能。

import redis
import time

pool = redis.ConnectionPool(host='localhost', port=6379, decode_responses=True)
r = redis.Redis(connection_pool=pool)
# pipe = r.pipeline(transaction=False)    # 默认的情况下,管道里执行的命令可以保证执行的原子性,执行pipe = r.pipeline(transaction=False)可以禁用这一特性。
# pipe = r.pipeline(transaction=True)
pipe = r.pipeline() # 创建一个管道

pipe.set('name', 'jack')
pipe.set('role', 'sb')
pipe.sadd('faz', 'baz')
pipe.incr('num')    # 如果num不存在则vaule为1,如果存在,则value自增1
pipe.execute()

print(r.get("name"))
print(r.get("role"))
print(r.get("num"))
Copy after login

运行结果:

jack
sb
1
Copy after login
Copy after login

管道的命令可以写在一起,如:

import redis
import time

pool = redis.ConnectionPool(host='localhost', port=6379, decode_responses=True)
r = redis.Redis(connection_pool=pool)
pipe = r.pipeline() # 创建一个管道
pipe.set('hello', 'redis').sadd('faz', 'baz').incr('num').execute()
print(r.get("name"))
print(r.get("role"))
print(r.get("num"))
Copy after login

运行结果:

jack
sb
1
Copy after login
Copy after login

The above is the detailed content of Python operation redis instance analysis. For more information, please follow other related articles on the PHP Chinese website!

Related labels:
source:yisu.com
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Popular Tutorials
More>
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template
About us Disclaimer Sitemap
php.cn:Public welfare online PHP training,Help PHP learners grow quickly!