[Database] scrapy redis redis how to operate and use databases

• Redis database
  • Windows installation and configuration under redis
  • Linux installation and configuration under redis
• Redis connection tool
  • Redis Desktop Manager installed
• Python third party libraries
  • pip install redis

The need to install something into ah shown on FIG.

First, the command line installation redis database, the command line format is as follows:

pip install redis

If the installation is complete redis under the windows, use the command line to test:

安装命令：redis-server.exe --service-install redis.windows.conf --loglevel verbose

启动服务命令：redis-server.exe  --service-start

关闭服务命令：redis-server.exe  --service-stop

Signs and successful installation process is as follows:

About Redis Desktop Manager is installed refer to this URL  https://blog.csdn.net/weixin_42284867/article/details/81219810

First redis database connection:

pool = redis.ConnectionPool(host=‘127.0.0.1‘, port=6379)
r = redis.StrictRedis(connection_pool=pool)

Redis database on this one operation, you can refer https://blog.csdn.net/zhaoliang831214/article/details/82051449

Redis database to obtain data instances of:

redis data to be stored in the form of hash worth redis are detailed below

Get the code below

#其中的db=0可以参考列表左边，redis一共有15个数据库
pool = redis.ConnectionPool(host='localhost',port=6379,password='',db=0)#创建连接池
r = redis.StrictRedis(connection_pool=pool,decode_responses=True)
#第一例 #useful_proxy是一个hash值，于表名
#result =r.hkeys("useful_proxy")
#返回[b'116.196.85.166:3128', b'180.97.33.212:80', b'124.205.155.146:9090'...一系列key值，如上图key那一列
#第二例 获取表中所有的值
result = r.hgetall("useful_proxy")
#返回{b'116.196.85.166:3128': b'{"proxy": "116.196.85.166:3128", "fail_count": 0, "region": ""...后边所有都是类似‘key1’：{“属性1名”：“value”，“属性2名”：“value”}，‘key2’：{“属性1名”：“value”，“属性2名”：“value”}...就是hash的结构属性+集合的构造
#第三例 获取表中单个列的value
#result = r.hmget("useful_proxy","116.196.85.166:3128")[0]
#返回{"proxy": "116.196.85.166:3128", "fail_count": 0。。。一个集合类似{“属性1名”：“value”，“属性2名”：“value”}
#第四例
#这里添加.decode()是为了添加value前边那个b’值，把bytes值变为string值
result = r.hmget("useful_proxy","116.196.85.166:3128")[0].decode()
#这里把string变为dict字典型
result = json.loads(result)
result = result.get("proxy")
print(result)

This hash value can be put in the second embodiment, when converted to string, then go dict, to deal with the python language. Haha embarrassment