Redis python operation python operation Redis Database

Original article in this: https://www.cnblogs.com/cnkai/p/7642787.html

There is a personal modification and correction

Connecting to a database

Strictredis
From Redis import Strictredis

#! / usr / bin / env python
# coding: utf-8

from redis import StrictRedis
from redis import ConnectionPool

# Link to database using default method 1
# redis = StrictRedis (host = ‘localhost’, port = 6397, db = 0)

# Link to database using default method 2
# pool = ConnectionPool (host = ‘localhost’, port = 6397, db = 0)
# redis = StrictRedis (ConnectionPool)

# Link to database using url method 1
# redis = StrictRedis.from_url (url = ‘redis: // localhost: 6379/1‘)


# Use url method 2 to connect to the database
pool = ConnectionPool.from_url (‘redis: // @ localhost: 6379/1‘)
redis = StrictRedis (connection_pool = pool)


"" "
Constructing a url to connect to the database has the following three modes:
redis: // [: password] @host: port / db # TCP connection
rediss: // [: password] @host: port / db # Redis TCP + SSL connection
unix: // [: password] @ / path / to / socket.sock? db = db # Redis Unix Socket connection
"" " 

Redis inside the specific operation

String manipulation

Method	function	Example	Example Results
Set (name, value)	Assign name to value	Redis.set (' name ', ' Bob ')	True
Get (name)	Returns the value of a string with key name in the database	Redis.get (' name ')	B ' Bob '
Getset (name, value)	Assigns a value to a string of key name in the database and returns the last value	Redis.getset (' name ', ' Mike ')	B ' Bob '
Mget (keys, *args)	Returns the value corresponding to multiple keys	Redis.mget ([' Name ', ' nickname '])	[B ' Mike ', B ' miker ']
SETNX (name, value)	Set value if key does not exist	Redis.setnx (' newname ', ' James ')	First run true, second false
Setex (name, time, value)	Sets a value that can correspond to a string type and specifies the validity period for this key value	Redis.setex (' name ', 1, ' James ')	True
SETRANGE (name, offset, value)	Sets the substring of the value of the specified key	Redis.set (' name ', ' Hello ') redis.setrange (' name ', 6, ' world ')	11, modified string length
Mset (mapping)	Batch Assignment	Redis.mset ({' name1 ': ' Durant ', ' name2 ': ' James '})	True
MSETNX (mapping)	Bulk assignment If key is not present	Redis.msetnx ({' Name3 ': ' Smith ', ' name4 ': ' Curry '})	True
INCR (name, amount=1)	Key is the value increment operation for name, the default 1,key does not exist and is created and set to amount	REDIS.INCR (' age ', 1)	1, which is the modified value
DECR (name, amount=1)	Key is the value of the value impairment operation, and the default 1,key does not exist and is created and set to-amount	REDIS.DECR (' age ', 1)	-1, which is the modified value
Append (key, value)	Key appends value for string of name	Redis.append (' nickname ', ' OK ')	13, which is the modified string length
SUBSTR (name, start, end=-1)	Returns a substring of the value of string with key name	Redis.substr (' name ', 1, 4)	B ' Ello '
GetRange (key, start, end)	Gets the value of the key from start to end of the substring	Redis.getrange (' name ', 1, 4)	B ' Ello '

Key operation

Method	function	Example	Example Results
Exists (name)	Determine if a key exists	Redis.exists (' name ')	True
Delete (name)	Delete a key	Redis.delete (' name ')	1
Type (name)	Determine the key type	Redis.type (' name ')	B ' String '
Keys (pattern)	Get all rules-compliant keys	Redis.keys (' n ')	[b ' name ']
Randomkey ()	Get a random key	Randomkey ()	B ' Name '
Rename (src, DST)	Rename the key	Redis.rename (' name ', ' nickname ')	True
Dbsize ()	Gets the number of keys in the current database	Dbsize ()	100
Expire (name, time)	Set the expiration time of the key, in seconds	Redis.expire (' name ', 2)	True
TTL (name)	Gets the expiration time of the key, in seconds, 1 for a permanent period	Redis.ttl (' name ')	-1
Move (name, DB)	Move key to a different database	Move (' name ', 2)	True
FLUSHDB ()	Delete all keys in the currently selected database	FLUSHDB ()	True
Flushall ()	Remove all keys from all databases	Flushall ()	True

List operation

Method	function	Example	Example Results
Rpush (name, *values)	Adds an element of value to the list end of the name of key, which can pass multiple	Redis.rpush (' list ', 1, 2, 3)	3,list size
Lpush (name, *values)	Add an element of value to the list header of the key name, and you can pass multiple	Redis.lpush (' list ', 0)	4,list size
Llen (name)	Returns the length of the list with key name	Redis.llen (' list ')	4
Lrange (name, start, end)	Returns the element between start and end in the list of key name	Redis.lrange (' list ', 1, 3)	[B ' 3 ', B ' 2 ', B ' 1 ']
LTrim (name, start, end)	Intercepts the list of key name, preserving the content indexed as start to end	LTrim (' list ', 1, 3)	True
Lindex (name, index)	Returns the element of the index position in the list of key name	Redis.lindex (' list ', 1)	B ' 2 '
LSet (name, index, value)	Assign a value to the element in the index position in the list of key name, and the error is out of bounds	Redis.lset (' list ', 1, 5)	True
Lrem (name, count, value)	Deletes the value in the list of Count keys as an element	Redis.lrem (' list ', 2, 3)	1, that is, the number of deletions
Lpop (name)	Returns and removes the first element in the list of key name	Redis.lpop (' list ')	B ' 5 '
Rpop (name)	Returns and removes the trailing element in the list of key name	Redis.rpop (' list ')	B ' 2 '
Blpop (keys, timeout=0)	Returns and deletes the first element in the list named in Keys, and if the list is empty, it will block waiting	Redis.blpop (' list ')	[B ' 5 ']
Brpop (keys, timeout=0)	Returns and deletes the tail element in the list of key name, and if the list is empty, it will block waiting	Redis.brpop (' list ')	[B ' 2 ']
Rpoplpush (SRC, DST)	Returns and deletes the tail element of the list named SRC, and adds the element to the head of the list named DST	Redis.rpoplpush (' list ', ' List2 ')	B ' 2 '

Set operation

Method	function	Example	Example Results
Sadd (name, *values)	Add an element to a set with key name	Redis.sadd (' tags ', ' book ', ' Tea ', ' Coffee ')	3, that is, the number of data inserted
Srem (name, *values)	Remove an element from a set of key name	Redis.srem (' tags ', ' book ')	1, that is, the number of deleted data
Spop (name)	Randomly returns and deletes an element in the set of key name	Redis.spop (' tags ')	B ' Tea '
Smove (SRC, DST, value)	Removes the element from the SRC corresponding set and adds it to the corresponding set in DST	Redis.smove (' tags ', ' tags2 ', ' Coffee ')	True
SCard (name)	Returns the number of elements of a set with key name	Redis.scard (' tags ')	3
Sismember (name, value)	Test whether the member is a set element of key name	Redis.sismember (' tags ', ' book ')	True
Sinter (keys, *args)	Returns the intersection of the set for all given keys	Redis.sinter ([' Tags ', ' tags2 '])	{b ' Coffee '}
Sinterstore (dest, Keys, *args)	To find the intersection and save the intersection to the collection of dest	Redis.sinterstore (' Inttag ', [' tags ', ' tags2 '])	1
Sunion (keys, *args)	Returns the set's set of all given keys	Redis.sunion ([' Tags ', ' tags2 '])	{b ' Coffee ', b ' book ', B ' Pen '}
Sunionstore (dest, Keys, *args)	Gather and save the set to the Dest collection	Redis.sunionstore (' Inttag ', [' tags ', ' tags2 '])	3
Sdiff (keys, *args)	Returns the set difference for all given keys	Redis.sdiff ([' Tags ', ' tags2 '])	{b ' book ', B ' Pen '}
Sdiffstore (dest, Keys, *args)	Finding the difference set and saving the difference set to the collection of dest	Redis.sdiffstore (' Inttag ', [' tags ', ' tags2 '])	3
Smembers (name)	Returns all elements of a set with key name	Redis.smembers (' tags ')	{b ' Pen ', b ' book ', B ' Coffee '}
Srandmember (name)	Randomly returns an element of the set of key name, but does not delete the element	Redis.srandmember (' tags ')

Sorted Set operation

Method	function	Example	Example Results
Zadd (name, args, *kwargs)	Add the element Member,score to the zset of the key name for sorting. If the element exists, its order is updated	Redis.zadd (' grade ', +, ' Bob ', 98, ' Mike ')	2, that is, the number of elements added
Zrem (name, *values)	Remove the element from the Zset key for name	Redis.zrem (' Grade ', ' Mike ')	1, that is, the number of deleted elements
Zincrby (name, value, amount=1)	If the element value already exists in the Zset of key name, the score of the element is incremented amount, otherwise the element is added to the collection, and its score value is amount	Redis.zincrby (' Grade ', ' Bob ',-2)	98.0, which is the modified value
Zrank (name, value)	Returns the rank of the element in the Zset key for name (sorted by score from small to large) that is subscript	Redis.zrank (' Grade ', ' Amy ')	1
Zrevrank (name, value)	Returns the inverse rank of the element in the Zset of key name (sorted by score from large to small) that is subscript	Redis.zrevrank (' Grade ', ' Amy ')	2
Zrevrange (name, start, end, Withscores=false)	Returns all elements of index from start to end in the Zset of key name (sorted by score from large to small)	Redis.zrevrange (' Grade ', 0, 3)	[B ' Bob ', b ' Mike ', b ' Amy ', B ' James ']
Zrangebyscore (name, Min, Max, Start=none, Num=none, Withscores=false)	Returns the element score a given interval in the Zset key for name	Redis.zrangebyscore (' Grade ', 80, 95)	[B ' Amy ', B ' James ']
Zcount (name, Min, max)	Returns the number of score in a given interval in the zset of the key name	Redis.zcount (' Grade ', 80, 95)	2
Zcard (name)	Returns the number of elements of the Zset key for name	Redis.zcard (' Grade ')	3
Zremrangebyrank (name, Min, max)	Removes the element that is ranked in the given interval in the Zset key for name	Redis.zremrangebyrank (' Grade ', 0, 0)	1, that is, the number of deleted elements
Zremrangebyscore (name, Min, max)	Delete the element in the given interval in the Zset of key name score	Redis.zremrangebyscore (' Grade ', 80, 90)	1, that is, the number of deleted elements

Hash operation

Method	function	Example	Example Results
Hset (name, key, value)	Add a map to the hash of key name	Hset (' Price ', ' cake ', 5)	1, that is, the number of mappings added
HSETNX (name, key, value)	Add a mapping to the hash of key name if the mapping key name does not exist	Hsetnx (' Price ', ' book ', 6)	1, that is, the number of mappings added
Hget (name, key)	Returns the value of field corresponding to the hash of key name	Redis.hget (' Price ', ' cake ')	5
Hmget (name, keys, *args)	Returns the value of each key in the hash of key name	Redis.hmget (' Price ', [' Apple ', ' orange '])	[B ' 3 ', B ' 7 ']
Hmset (name, mapping)	Bulk add mappings to a hash of key name	Redis.hmset (' price ', {' banana ': 2, ' pear ': 6})	True
Hincrby (name, key, Amount=1)	Adds amount to the value mapped in the hash of key name	Redis.hincrby (' Price ', ' Apple ', 3)	6, the modified value
Hexists (name, key)	Key is a map with key name Namehash in the	Redis.hexists (' price ', ' banana ')	True
Hdel (name, *keys)	Key to delete the map with key named Key in Namehash	Redis.hdel (' price ', ' banana ')	True
Hlen (name)	Gets the number of mappings from a hash of key name	Redis.hlen (' price ')	6
Hkeys (name)	Get all the mapping key names from the hash of key name	Redis.hkeys (' price ')	[B ' Cake ', b ' book ', B ' banana ', b ' pear ']
Hvals (name)	Get all mapping key values from a hash of key name	Redis.hvals (' price ')	[B ' 5 ', B ' 6 ', B ' 2 ', B ' 6 ']
Hgetall (name)	Gets all mapped key-value pairs from a hash of key name	Redis.hgetall (' price ')	{b ' cake ': B ' 5 ', b ' book ': B ' 6 ', B ' orange ': B ' 7 ', B ' pear ': B ' 6 '}

Redisdump & Redis-load Data export and data import

• Redis-load
  Import data into the database
• Redis-dump Export the data (the Redis-dump tool is written in Ruby.)  So after the system is installed Ruby, use Ruby's gem install Redis-dump to export the database. Redis-dump-u: [Email protected]:6379 >test.json

Redis-load operations are as follows

# Import data using Unix pip
# cat test.json | redis-load -u: [email protected] 127.0.0.1:6379
# Or so use Unix redirection
# redis-load -u: [email protected]: 6379 <test.json 

Redis-dump operations are as follows

Install redis-dump [[email protected] ~] yum install ruby rubygems ruby-devel // Install rubygems and related packages (redhat series systems, or apt for debian, etc.)
   
[[email protected] ~] gem sources -a http://gems.ruby-china.org/ // source, ruby china joined, outside sources cannot be accessed
http://gems.ruby-china.org/ added to sources
   
[[email protected] ~] gem install redis-dump -V
  redis-dump export data
[[email protected] ~] telnet 127.0.0.1 6379
Trying 127.0.0.1 ...
Connected to 127.0.0.1.
Escape character is ‘^]‘.
set test 11 // Set a value
+ OK
get test // take value
$ 2
11
[[email protected] ~] redis-dump -u: passwd@127.0.0.1: 6379> test.json 

This will export the contents of the database to Test.json.

Redis python operation python operation Redis Database