Book Image

Building Python Web APIs with FastAPI

By : Abdulazeez Abdulazeez Adeshina
Book Image

Building Python Web APIs with FastAPI

By: Abdulazeez Abdulazeez Adeshina

Overview of this book

RESTful web services are commonly used to create APIs for web-based applications owing to their light weight and high scalability. This book will show you how FastAPI, a high-performance web framework for building RESTful APIs in Python, allows you to build robust web APIs that are simple and intuitive and makes it easy to build quickly with very little boilerplate code. This book will help you set up a FastAPI application in no time and show you how to use FastAPI to build a REST API that receives and responds to user requests. You’ll go on to learn how to handle routing and authentication while working with databases in a FastAPI application. The book walks you through the four key areas: building and using routes for create, read, update, and delete (CRUD) operations; connecting the application to SQL and NoSQL databases; securing the application built; and deploying your application locally or to a cloud environment. By the end of this book, you’ll have developed a solid understanding of the FastAPI framework and be able to build and deploy robust REST APIs.
Table of Contents (14 chapters)
Part 1: An Introduction to FastAPI
Part 2: Building and Securing FastAPI Applications
Part 3: Testing And Deploying FastAPI Applications

Path and query parameters

In the previous section, we learned what models are and how they are used to validate request bodies. In this section, you’ll learn what path and query parameters are, the role they play in routing, and how to use them.

Path parameters

Path parameters are parameters included in an API route to identify resources. These parameters serve as an identifier and, sometimes, a bridge to enable further operations in a web application.

We currently have routes for adding a todo and retrieving all the todos in our todo application. Let’s create a new route for retrieving a single todo by appending the todo’s ID as a path parameter.

In, add the new route:

from fastapi import APIRouter, Path
from model import Todo
todo_router = APIRouter()
todo_list = []"/todo")
async def add_todo(todo: Todo) -> dict:
    return {