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

Handling multiple WebSocket connections and broadcasting messages

As we said in the introduction to this chapter, a typical use case for WebSockets is to implement real-time communication across multiple clients, such as a chat application. In this configuration, several clients have an open WebSocket tunnel with the server. Thus, the role of the server is to manage all the client connections and broadcast messages to all of them: when a user sends a message, the server has to send it to all other clients in their WebSockets. We show you a schema of this principle here:

Figure 8.3 – Multiple clients connected through WebSocket to a server

A first approach could be simply to keep a list of all WebSocket connections and iterate through them to broadcast messages. This would work but would quickly become problematic in a production environment. Indeed, most of the time, server processes run multiple workers when deployed. This means that instead of having...