Book Image

Building Data Science Applications with FastAPI

By : François Voron
5 (1)
Book Image

Building Data Science Applications with FastAPI

5 (1)
By: François Voron

Overview of this book

FastAPI is a web framework for building APIs with Python 3.6 and its later versions based on standard Python-type hints. With this book, you’ll be able to create fast and reliable data science API backends using practical examples. This book starts with the basics of the FastAPI framework and associated modern Python programming language concepts. You'll be taken through all the aspects of the framework, including its powerful dependency injection system and how you can use it to communicate with databases, implement authentication and integrate machine learning models. Later, you’ll cover best practices relating to testing and deployment to run a high-quality and robust application. You’ll also be introduced to the extensive ecosystem of Python data science packages. As you progress, you’ll learn how to build data science applications in Python using FastAPI. The book also demonstrates how to develop fast and efficient machine learning prediction backends and test them to achieve the best performance. Finally, you’ll see how to implement a real-time face detection system using WebSockets and a web browser as a client. By the end of this FastAPI book, you’ll have not only learned how to implement Python in data science projects but also how to maintain and design them to meet high programming standards with the help of FastAPI.
Table of Contents (19 chapters)
1
Section 1: Introduction to Python and FastAPI
7
Section 2: Build and Deploy a Complete Web Backend with FastAPI
13
Section 3: Build a Data Science API with Python and FastAPI

Chapter 5: Dependency Injections in FastAPI

In this chapter, we'll focus on one of the most interesting parts of FastAPI: dependency injections. You'll see that it is a powerful and readable approach to reuse logic across your project. Indeed, it will allow you to create complex building blocks for your project that you'll be able to use everywhere in your logic. An authentication system, a query parameters' validator, or a rate-limiter are typical use cases for dependencies. In FastAPI, a dependency injection can even call another one recursively, allowing you to build high-level blocks from basic features. By the end of this chapter, you'll be able to create your own dependencies for FastAPI and use them at several levels of your project.

In this chapter, we're going to cover the following main topics:

  • What is dependency injection?
  • Creating and using a function dependency
  • Creating and using a parameterized dependency with a class
  • ...