Python redis set get

Redis python | How to interact with redis using python in 2022

Redis is one of the most popular open-source key-value type storage. A user can interact with redis using multiple languages. In this tutorial, we will learn about the redis python client. We will understand how to interact with redis using python. so let’s get started.

Redis python client

redis-py is the python client a user can use to interact with redis. redis-py requires a running Redis instance so please make sure redis is running in your system. You can follow my tutorial to install redis on your system.

To install the redis-py type the below command

Now, connect to the python shell and type the below command to verify if the installation is successful.

If you are able to import the packages without any error it means the installation is successful.

Redis python example

In this session, we will understand how to interact with redis using python and perform various operations on the redis data.

Python redis auth

python support authentication to redis using basic auth, user, and pass auth as well as auth in the SSL-enabled environment.

python redis basis auth

To authenticate to redis we need to pass the redis host, port, and database to connect to. In most cases, the database is db0. You can follow the below tutorial to understand the redis databases.

In this case, the redis runs on host 127.0.0.1 and port 6379. Now type the below command to authenticate to redis.

import redis r = redis.Redis(host='localhost', port=6379, db=0)

python redis auth using username and password

If the redis is configured to connect using username and password, then type the below command to connect to redis

redis.Redis(host='localhost', port=6380, username='', password='<>pswd')

python redis SSL enabled auth

If the redis instance is configured with SSL, then we need to pass the ca certificate along with the host and port to connect to redis.

r = redis.Redis(host='127.0.0.1', port=6379, db=0, ssl=True, ssl_ca_certs='')

Redis python insert a key

To insert a key into the redis using python a user needs to use the set command

If you are getting TRUE as output, it means the key is successfully inserted.

Redis python get a key

get command is used to retrieve a particular key from the redis database.

Redis python get all keys

A user can also get all the keys present in redis using the get command.No need to pass any argument in the get command to get all the keys

Redis python scan

The scan is another powerful command that exists in redis. For SCAN/SSCAN/HSCAN/ZSCAN command, py-redis has implemented similar commands which are scan_iter/sscan_iter/hscan_iter/zscan_iter.

Now let’s use the scan_iter command to retrieve all the keys from the redis database.

for key, value in (('k1', 'v1'), ('k2', 'v2'), ('k3', 'v3')): r.set(key, value) for key in r.scan_iter(): print(key, r.get(key))

Redis python pipeline

The pipeline is a method using which we can run multiple commands at once without waiting for the response to each command. This improves the redis performance.

The same can be achieved using the redis python client. Below is a simple example of the redis pipeline.

pipe = r.pipeline() pipe.set('key_1', "value1") pipe.set('key_2', "value2") pipe.set('key_3', "value3") pipe.execute()

Redis python additional resources

You can check the below additional resources to learn more about the redis python client.

Python redis github

Check the redis python GitHub page to understand how the redis python library is written and check the readme for a quick overview of the redis client.

Python redis pypi

Check the Python redis PyPI official doc for some advanced redis python client library usage.

Conclusion

I hope you have liked this brief tutorial on the redis python client. Please do let me know if you are facing any issues while following along

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How to Use Redis With Python

Redis is a open-source, in-memory database storing data as key-value pairs. It is a popular choice as a caching mechanism or a message broker.

Redis can perform swift and memory-efficient operations with minimal configurations when paired with a language like Python.

Requirements

This article assumes you have the latest version of the Redis server, and Python 3 is installed and configured on your system.

We also assume basic Python and Redis knowledge.

Installing Redis-Py

To connect and use Redis with Python, we need a Python-Redis client. For this process, we will opt for redis-py as it is easy to use and configure.

You can check other python-redis clients on the resource page below:

To install, open the terminal and run the following command:

The previous command should download and install the Redis-py client.

Connecting to Redis

The next step is to connect to our Redis server. Start by creating a working directory as:

Create a Python file and give it any name you see fit.

Open the file with your text editor and add the code shown below:

In the previous example code, we start by importing the Redis module.

Next, we create a new Redis client using the redis.Redis method. Then, we pass the parameters to connect to the Redis server.

NOTE: Ensure to replace the host, port, and password with the details for your Redis server.

To test the server is running, add the following:

Redis Set Key-Value Pairs

Once you are connected, you can perform all supported operations on the Redis server. For simplicity, let us set a new key-value pair.

The set function takes key and value as arguments and adds them to the database.

Redis Get Key-Value Pairs

To get the value associated with a specific key, use the get method as shown below:

The previous code should return:

Python Redis SETEX

We can also set a key and value pair that expires at a specific duration. To do this, we can use the SETEX function as shown below:

Here, we set a new key and value that expires in 60 seconds.

To check the TTL, we can do the following:

This should return how many seconds the key has to live.

Redis Python Switch Database

To switch Redis databases in Python, use the select function as:

The previous command should switch to the database at index 10.

Conclusion

This guide covered the basics of connecting and using Redis with Python through the Redis set key-value pairs and the Python Redis SETEX. We hope you found this article helpful. Check the other Linux Hint articles for tips and tutorials.

About the author

John Otieno

My name is John and am a fellow geek like you. I am passionate about all things computers from Hardware, Operating systems to Programming. My dream is to share my knowledge with the world and help out fellow geeks. Follow my content by subscribing to LinuxHint mailing list

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Python Redis Set Commands

Sets are lists filled with unique items. The set data type is helpfuly when you want to work with unique data types, thus they help with features where you want to easily deuplicate values. In this article, we will learn how to work with sets in Redis and Python.

Setting up Redis

For setting up Redis, I would recommend using a service for you in prod. Azure for example, has a great redis service that scales easily. However, you will want to learn redis and eventually how to scale it yourself. This will help with debugging cloud services or eventually, saving money and not using them.

We will start our intro to redis via using docker compose. Create a docker-compose.yml file and add the following.

version: "3.2" services: redis: image: "redis:alpine" command: redis-server ports: - "6379:6379" volumes: - $PWD/redis-data:/var/lib/redis - $PWD/redis.conf:/usr/local/etc/redis/redis.conf environment: - REDIS_REPLICATION_MODE=master

Ensure you have docker installed and run

Installing Redis Modules

In python, the main used redis module is called redis-py and can be installed using the follows.

Writing the Code

Let’s open up a new file, index.py and go through many of the common commands you will used with lists in redis.

Writing the Code

Let’s open up a new file, index.py and go through many of the common commands you will used with lists in redis.

Set Add

We can push items to a list using lpush . The first param is the name of the key and then we can pass in as many items as we want for the list.

# Set Add res = r.sadd("users", "user1") print(res)

For each of the example below, I will use the following template to run all the commands. Here is my full index.js file. We will just replace the commands each time.

import redis r = redis.Redis(host='localhost', port=6379, db=0) # Set Add res = r.sadd("users", "user1") print(res)

Set Cardinality (Size)

If we want to get the size of our set, we can use scard .

# Set Cardinaility const result = r.scard("users") print(result) # output: 2

Set Difference

We can get the difference or the values that are not in both sets using the sdiff command. This can be helpful for tracking usage metrics.

r.sadd("users-feature1", "user1", "user2") r.sadd("users-feature2", "user1") # Set Difference const result = r.sdiff("users-feature1", "users-feature2") print(result) # output: ["user2"]

Set Intersection

Similar to above, we can get the intersection between two sets, the values that are in both sets, using the SINTER command.

r.sadd("users-feature1", "user1", "user2") r.sadd("users-feature2", "user1") # Set Intersection const result = r.sinter("users-feature1", "users-feature2") print(result) # output: ["user1"]

Set Union

Keeping with the theme of set operations, we can take the union of two sets, returning a combination of sets, using the SUNION command.

r.sadd("users-feature1", "user1", "user2") r.sadd("users-feature2", "user1", "user3") # Set Union const result = r.sunion("users-feature1", "users-feature2") print(result) # output: ["user1", "user2", "user3"]

Set Is Member and Multiple is Members

We can check if a key is a member of a set using the SISMEMBER command.

r.sadd("users", "user1", "user2") # Set Is Member const result = r.sismember("users", "users1") print(result) # output: true

We can check multiple members (if you use redis 6 or later) with the SMISMEMBER which means Set Multiple Is Member.

r.sadd("users", "user1", "user2") # Set Multiple Is Member const result = r.sismember("users", "users1", "user2", "user3") print(result) # output: [true, true, false]

Set Members

To get a list of all members, we can use the SMEMBERS command.

r.sadd("users", "user1", "user2") # Set Members const result = r.smembers("users") print(result) # output: ["user1", "user2"]

Set Remove

We can remove a member from one set to another using the SREM command.

r.sadd("users", "user1", "user2") # Set Remove r.srem("users", "user1") const result = r.smembers("users") print(result) # output: ["user2"]

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