Driving module

• redis Module is used to drive Redis database in Python environment
• Can be installed directly in pip mode

pip install redis

Or download domestic image:

pip install -i https://pypi.tuna.tsinghua.edu.cn/simple some-package

Create connection

import redis
con = redis.Redis(
    host="localhost",
    port="6379",
    password="123456",
    db=0
)

redis connection pool

• Create connection pool

import redis
pool = redis.ConnectionPool(
    host="localhost",
    port="6379",
    password="123456",
    db=0
    max_connection=20
)

• After the redis connection pool operation is completed, you do not need to close the connection. After deleting the connection object with del, it will automatically return to the connection pool.

con = redis.Redis(
    connection_pool=pool
)
......
del con

redis operation command

• Character string

con.set("country","China")
con.set("city","Shanghai)
city = con.get("city").decode('utf-8')
print(city)
con.delete("city")

con.mset("countyr":"China","city":"Shanghai")
result = con.mget("country","city")
for one in result:
    print(one.decode('utf-8'))

• Hash

con.hmset("86",{"country":"China","city":"Shanghai","code":"200000"})
con.hset("86","age":"70")
con.hdel("86","code")
con.hexists("86","city")
result = con.hgetall("86")
for one in result:    
    print(one.decode("utf-8"))

• list

con.rpush("courtry","China","Japan","The Republic of Korea","India")
con.lpop("country")
result = con.lrange("country",0,-1)
for one in result:
    print(one.decode('utf-8'))

• aggregate

con.sadd("courtry","China","Japan","The Republic of Korea","India")
con.rem("country","China")
result = con.smembers("country")
for one in result:
    print(one.decode('utf-8'))

• Ordered set

con.zadd("country",{"China":"0","Japan":"0","The Republic of Korea":"0"})
con.zincrby("country","10","China")
result = con.zrevrange("country",0,-1)
for one in result:
    print(one.decode('utf-8'))

Transaction function of redis PY

• The redis py module uses pipeline to deliver batch commands and execute transactions to the redis server.

pipline = con.pipline()
pipline.watch(......)
pipline.multi()
pipline.execute()
pipline.reset()

Case study on the combination of redis database exception handling and transaction

import redis

pool = redis.ConnectionPool(
    host="localhost",
    port="6379",
    password="123456",
    db=0
    max_connection=20
)

con = redis.Redis(
    connection_pool=pool
)
pipline=con.pipline()

try:
    pip.watch("xxx")
    pip.multi()
    pipline.zincrby("country","1","China")
    pipline.execute()
except Exception as e:
    print(e)
finally:
    if "pipline" in dir():
        pipline.reset()
    del con