Redis 数据库hash数据类型是一个string类型的key和value的映射表,适用于存储对象。Redis 中每个 hash 可以存储 232 - 1 键值对(40多亿)。
Python的redis模块实现了Redis哈希(Hash)命令行操作的几乎全部命令,包括HDEL、HEXISTS、HGET、HGETALL、HINCRBY、HKEYS、HLEN 、HMGET 、HMSET 、HSET 、HSETNX 、HVALS 。但是无法支持HINCRBYFLOAT 、HSCAN 等命令。
函数说明
- HDEL: 删除对应哈希(Hash)表的指定键(key)的字段,hdel(self, name, key)
- HEXISTS: 检测哈希(Hash)表对应键(key)字段是否存在,返回布尔逻辑,hexists(self, name, key)
- HGET: 获取哈希(Hash)指定键(key)对应的值,hget(self, name, key)
- HGETALL: 获取哈希(Hash)表的键-值对(key-value pairs),返回python字典类型数据,hgetall(self, name)
- HINCRBY: 为哈希表(Hash)指定键(key)对应的值(key)加上指定的整数数值(int,可为负值),参见 [Python操作Redis:字符串(String)],(http://blog.csdn.net/u012894975/article/details/51285733)hincrby(self, name, key, amount=1),Redis 中本操作的值被限制在 64 位(bit)有符号数字。
- HKEYS: 返回哈希表(Hash)对应键(key)的数组(Python称之为列表List),hkeys(self, name)
- HLEN: 获取哈希表(Hash)中键-值对(key-value pairs)个数,hlen(self, name)
- HMGET: 获取哈希表(Hash)中一个或多个给点字段的值,不存在返回nil(Redis命令行)/None(Python),hmget(self, name, keys),其中keys可以为列表(list)
- HMSET: 设置对个键-值对(key-value pairs)到哈希表(Hash)中,python输入值(mapping)为字典(dictionary)类型,hmset(self, name, mapping)
- HSET: 为哈希表(Hash)赋值,若键(key)存在值(value)则覆盖,不存在则创建,hset(self, name, key, value)
- HSETNX:为哈希表(Hash)不存值(value)的键(key)赋值,存在操作无效,对应值(value)无变化,hsetnx(self, name, key, value)
- HVALS:返回哈希表(Hash)对应值(value)的列表,hvals(self, name)
# -*- coding:utf-8 -*- import sys reload(sys) sys.setdefaultencoding('utf-8') import redis import time ## Connect local redis service client =redis.Redis(host='127.0.0.1',port=6379,db=0) print "Connection to server successfully!" dicKeys = client.keys("*") print dicKeys #-----------------------------10----------------------------------------- ### Redis hash command part Start ### # hset: Set key to value with hash name,hset(self, name, key, value) # hget: Return the value of ``key`` within the hash ``name``, hget(self, name, key) client.hset('myhash','field1',"foo") hashVal = client.hget('myhash','field1') print "Get hash value:",hashVal #------------------------------3------------------------------------------ # Get none-value hashVal = client.hget('myhash','field2') print "None hash value:",hashVal #---------------------------------2-------------------------------------------- # hexists: Returns a boolean indicating if ``key`` exists within hash ``name`` keyList= ['field1','field2'] for key in keyList: hexists = client.hexists('myhash',key) if hexists : print "Exist in redis-hash key:",key else: print "Not exist in redis-hash key:",key # hgetall: Return a Python dict of the hash's name/value pairs client.hset('myhash','field2',"bar") valDict = client.hgetall('myhash') print "Get python-dict from redis-hash",valDict # hincrby: Increment the value of ``key`` in hash ``name`` by ``amount`` # default increment is 1, client.hset('myhash','field',20) #-----------------------------------5---------------------------------------- client.hincrby('myhash','field') print "Get incrby value(Default):",client.hget('myhash','field') client.hincrby('myhash','field',2) print "Get incrby value(step: 2):",client.hget('myhash','field') client.hincrby('myhash','field',-3) print "Get incrby value(step: -3):",client.hget('myhash','field') # no method hincrbyfloat #-----------------------------------6---------------------------------------- #hkeys: Return the list of keys within hash ``name`` kL = client.hkeys('myhash') print "Get redis-hash key list",kL #-----------------------------------7---------------------------------------- #hlen: Return the number of elements in hash ``name`` lenHash =client.hlen('myhash') print "All hash length:",lenHash #-----------------------------------8---------------------------------------- #hmget: Returns a list of values ordered identically to ``keys`` #hmget(self, name, keys), keys should be python list data structure val =client.hmget('myhash',['field','field1','field2','field3','fieldx']) print "Get all redis-hash value list:",val #-----------------------------------9---------------------------------------- #hmset: Sets each key in the ``mapping`` dict to its corresponding value in the hash ``name`` hmDict={'field':'foo','field1':'bar'} client.hmset('hash',hmDict) hmKeys=hmDict.keys()#设置完毕 #-----------------------------------8---------------------------------------- val = client.hmget('hash',hmKeys) print "Get hmset value:",val #-----------------------------------1---------------------------------------- #hdel: Delete ``key`` from hash ``name`` client.hdel('hash','field') print "Get delete result:",client.hget('hash','field') #----------------------------------12--------------------------------------- #hvals: Return the list of values within hash ``name`` val = client.hvals('myhash') print "Get redis-hash values with HVALS",val print"-----------------------------11----------------------------------------" #----------------------------------11--------------------------------------- #hsetnx: Set ``key`` to ``value`` within hash ``name`` if ``key`` does not exist. # Returns 1 if HSETNX created a field, otherwise 0. r=client.hsetnx('myhash','field',2)#这句话的意思是,试图为myhash的field赋值为2 print "Check hsetnx execute result:",r," Value:",client.hget('myhash','field') r=client.hsetnx('myhash','field10',20) print "Check hsetnx execute result:",r,"Value",client.hget('myhash','field10') hashVal = client.hgetall('profile') print hashVal #Empty db # client.flushdb()#这句话会把所有数据都清除掉