FastAPI CRUD API

🍃FastAPI Projects 📂 user-crud

Introduction

CRUD stands for Create, Read, Update and Delete.

Those are the basic operations you would perfom on a database entity. In this blog post, let’s take a super-simple User entity with name and age properties.

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FastAPI is a modern, fast (high-performance), web framework for building APIs with Python based on standard Python type hints.

The key features are:

• Fast: Very high performance, on par with NodeJS and Go (thanks to Starlette and Pydantic).
• Fast to code: Increase the speed to develop features.
• Fewer bugs: Reduce about 40% of human (developer) induced errors.
• Intuitive: Great editor support. Completion everywhere. Less time debugging.
• Easy: Designed to be easy to use and learn. Less time reading docs.
• Short: Minimize code duplication. Multiple features from each parameter declaration.
• Robust: Get production-ready code. With automatic interactive documentation.
• Standards-based: Based on (and fully compatible with) the open standards for APIs: OpenAPI (previously known as Swagger) and JSON Schema.

Installation

First installation of FastAPI:

# move into the correct directory
cd user-crud

# create the virtual environment and activate it
python3 -m venv .venv/
source .venv/bin/activate

# install the dependency
python3 -m pip install "fastapi[standard]"

Then run the server with:

fastapi dev main.py

N.B.: You could also use a Docker or Podman container.

Project Structure

The project structure is:

• Directoryuser-crud

  • Directoryrouters/ expose API endpoint

    • …
  • Directoryschemas/ implement models

    • …
  • Directoryservices/ implement business logic

    • …
  • main.py include routes

API calls

Here is a list of API calls based on the OS you’re using. If you prefer a graphical way to perfom API calls, I suggest you to use Postman application.

POST

Windows

Windows PowerShell

curl -Method POST http://localhost:8000/users `
-Headers @{ "Content-Type" = "application/json" } `
-Body '{ "name": "John", "age": 18 }'

Linux

Bash Terminal

curl -X POST http://localhost:8000/users \
-H "Content-Type: application/json" \
-d '{"name": "Bill", "age": 20}'

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GET by ID

Windows

Windows PowerShell

curl -Method GET http://localhost:8000/users/0

Linux

Bash Terminal

# get User from id=1
curl -X GET http://localhost:8000/users/0

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GET all

Windows

Windows PowerShell

curl -Method GET http://localhost:8000/users

Linux

Bash Terminal

# get User from id=1
curl -X GET http://localhost:8000/users

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UPDATE by ID

Windows

Windows PowerShell

curl -Method PUT http://localhost:8000/users/0 `
  -Headers @{ "Content-Type" = "application/json" } `
  -Body '{ "name": "New Name", "age": 18 }'

Linux

Bash Terminal

curl -X PUT http://localhost:8000/users/0 \
  -H "Content-Type: application/json" \
  -d '{"name": "New Name", "age": 20}'

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DELETE by ID

Windows

Windows PowerShell

curl -Method DELETE http://localhost:8000/users/0

Linux

Bash Terminal

curl -X DELETE http://localhost:8000/users/0

API Documentation

FastAPI provides API documentation pages out of the box.

FastAPI - Swagger UI Swagger-based APIs description

Or, if you prefer, you can also take a look at:

FastAPI - ReDoc ReDoc-based APIs description

Conclusion

Here you are with your first CRUD API application written with FastAPI!

Links related to this article:

• FastAPI
• dev.to article