Challenge: INCR and DECR

You are working with a platform where users can like or dislike various posts. Each post has a unique identifier, such as post:1, post:2, post:3.

The task is to build a system to track reactions on multiple posts by randomly adding likes and dislikes, and then displaying the total count of reactions for each post.

1. Create 3 posts, each with two counters: one for likes and one for dislikes. For example: post:1:likes, post:1:dislikes, and so on;

2. Use the INCR or INCRBYcommand to add likes and dislikes to each post. Add 3 likes and 2 dislikes to post:1, and 5 likes and 1 dislike to post:2;

3. Use the DECR or DECRBYcommand to decrease reactions for some posts. Remove 1 like from post:1 and 2 dislikes from post:2;

4. Use the GETcommand to retrieve the current number of likes and dislikes for each post.

The expected result should look like this:

python
9
1
2
3
Post 1: 2 likes, 2 dislikes
Post 2: 5 likes, 0 dislikes
Post 3: 0 likes, 0 dislikes

Create counters for likes and dislikes for each post:

redis
9
1
2
3
4
5
6
SET post:1:likes 0
SET post:1:dislikes 0
SET post:2:likes 0
SET post:2:dislikes 0
SET post:3:likes 0
SET post:3:dislikes 0

Add 3 likes and 2 dislikes to post:1:

python
9
1
2
INCRBY post:1:likes 3
INCRBY post:1:dislikes 2

Add 5 likes and 1 dislike to post:2:

python
9
1
2
INCRBY post:2:likes 5
INCRBY post:2:dislikes 1

Remove 1 like from post:1 and 2 dislikes from post:2:

python
9
1
2
DECRBY post:1:likes 1
DECRBY post:2:dislikes 2

Retrieve the current number of likes and dislikes for each post:

python
9
1
2
3
4
5
6
GET post:1:likes
GET post:1:dislikes
GET post:2:likes
GET post:2:dislikes
GET post:3:likes
GET post:3:dislikes