Book Image

Learning Python Application Development

By : Ninad Sathaye
Book Image

Learning Python Application Development

By: Ninad Sathaye

Overview of this book

Python is one of the most widely used dynamic programming languages, supported by a rich set of libraries and frameworks that enable rapid development. But fast paced development often comes with its own baggage that could bring down the quality, performance, and extensibility of an application. This book will show you ways to handle such problems and write better Python applications. From the basics of simple command-line applications, develop your skills all the way to designing efficient and advanced Python apps. Guided by a light-hearted fantasy learning theme, overcome the real-world problems of complex Python development with practical solutions. Beginning with a focus on robustness, packaging, and releasing application code, you’ll move on to focus on improving application lifetime by making code extensible, reusable, and readable. Get to grips with Python refactoring, design patterns and best practices. Techniques to identify the bottlenecks and improve performance are covered in a series of chapters devoted to performance, before closing with a look at developing Python GUIs.
Table of Contents (18 chapters)
Learning Python Application Development
Credits
Disclaimers
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Exceptions


Before jumping straight into the code and fixing these issues, let's first understand what an exception is and what we mean by handling an exception.

What is an exception?

An exception is an object in Python. It gives us information about an error detected during the program execution. The errors noticed while debugging the application were unhandled exceptions as we didn't see those coming. Later in the chapter, you will learn the techniques to handle these exceptions.

The ValueError and IndexError exceptions seen in the earlier tracebacks are examples of built-in exception types in Python. In the following section, you will learn about some other built-in exceptions supported in Python.

Most common exceptions

Let's quickly review some of the most frequently encountered exceptions. The easiest way is to try running some buggy code and let it report the problem as an error traceback! Start your Python interpreter and write the following code:

Here are a few more exceptions:

As you can...