REST API for a blog using FastAPI, a modern Python web framework for building APIs.

Step 1: Set Up Your Environment

Install Python: Ensure Python is installed on your system.
Install FastAPI and Uvicorn:
bash
```
pip install fastapi uvicorn
```

Step 2: Create the FastAPI Application

Create a new directory for your project:
bash
```
mkdir fastapi_blog
cd fastapi_blog
```
Create a file named main.py:
bash
```
touch main.py
```

Step 3: Write the Blog API

In main.py, write the following code:

python

Copyfrom fastapi import FastAPI, HTTPException from pydantic import BaseModel from typing import List, Optional app = FastAPI() # In-memory “database” for blog posts posts = [] # Model for a blog post class Post(BaseModel): id: int title: str content: str author: str # Helper function to find a post by ID def find_post(post_id: int): for post in posts: if post.id == post_id: return post return None # Create a new post @app.post(“/posts/”, response_model=Post) def create_post(post: Post): posts.append(post) return post # Get all posts @app.get(“/posts/”, response_model=List[Post]) def get_posts(): return posts # Get a single post by ID @app.get(“/posts/{post_id}”, response_model=Post) def get_post(post_id: int): post = find_post(post_id) if post is None: raise HTTPException(status_code=404, detail=“Post not found”) return post # Update a post by ID @app.put(“/posts/{post_id}”, response_model=Post) def update_post(post_id: int, updated_post: Post): post = find_post(post_id) if post is None: raise HTTPException(status_code=404, detail=“Post not found”) post.title = updated_post.title post.content = updated_post.content post.author = updated_post.author return post # Delete a post by ID @app.delete(“/posts/{post_id}”) def delete_post(post_id: int): post = find_post(post_id) if post is None: raise HTTPException(status_code=404, detail=“Post not found”) posts.remove(post) return {“message”: “Post deleted successfully”}

Step 4: Run the API

Start the FastAPI server using Uvicorn:

uvicorn main:app --reload

The --reload flag enables auto-reloading, so the server will restart whenever you make changes to the code.

Step 5: Test the API

You can test the API using curl, Postman, or the built-in Swagger UI provided by FastAPI.

Swagger UI: Open your browser and go to http://127.0.0.1:8000/docs. This will display an interactive API documentation where you can test all the endpoints.

Endpoints:

Create a Post: POST /posts/

{
  "id": 1,
  "title": "My First Post",
  "content": "This is my first blog post.",
  "author": "John Doe"
}

Get All Posts: GET /posts/
Get a Single Post: GET /posts/{post_id}

Update a Post: PUT /posts/{post_id}

{
  "id": 1,
  "title": "Updated Post",
  "content": "This post has been updated.",
  "author": "John Doe"
}

Delete a Post: DELETE /posts/{post_id}

Step 6: Example Workflow

Create a Post:

Send a POST request to /posts/ with a JSON body.

Example:

{
  "id": 1,
  "title": "My First Post",
  "content": "This is my first blog post.",
  "author": "John Doe"
}

Get All Posts:

Send a GET request to /posts/.

Response:

[
  {
    "id": 1,
    "title": "My First Post",
    "content": "This is my first blog post.",
    "author": "John Doe"
  }
]

Get a Single Post:

Send a GET request to /posts/1.