Book Image

Python Web Development with Sanic

By : Adam Hopkins
Book Image

Python Web Development with Sanic

By: Adam Hopkins

Overview of this book

Today’s developers need something more powerful and customizable when it comes to web app development. They require effective tools to build something unique to meet their specific needs, and not simply glue a bunch of things together built by others. This is where Sanic comes into the picture. Built to be unopinionated and scalable, Sanic is a next-generation Python framework and server tuned for high performance. This Sanic guide starts by helping you understand Sanic’s purpose, significance, and use cases. You’ll learn how to spot different issues when building web applications, and how to choose, create, and adapt the right solution to meet your requirements. As you progress, you’ll understand how to use listeners, middleware, and background tasks to customize your application. The book will also take you through real-world examples, so you will walk away with practical knowledge and not just code snippets. By the end of this web development book, you’ll have gained the knowledge you need to design, build, and deploy high-performance, scalable, and maintainable web applications with the Sanic framework.
Table of Contents (16 chapters)
Part 1:Getting Started with Sanic
Part 2:Hands-On Sanic
Part 3:Putting It All together

Implementing practical real-world exception handlers

Exception handling is not a new concept at this point. We explored the topic in the Implementing proper exception handling section in Chapter 6, Operating Outside the Response Handler. I emphasized the importance of creating our own set of exceptions that include default status messages and response codes. This useful pattern was meant to get you up and running very quickly to be able to send useful messages to your users.

For example, imagine we are building an application for travel agents to book airline tickets for customers. You can imagine one of the steps of the operation might be to assist in matching flights through connecting airports.

Well, what if the customer selected two flights where the time between the flights was too short? You might do something like this:

from sanic.exceptions import SanicException
class InsufficientConnection(SanicException):
    status_code = 400