Book Image

Modern Python Cookbook - Second Edition

By : Steven F. Lott
Book Image

Modern Python Cookbook - Second Edition

By: Steven F. Lott

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great language that can power your applications and provide great speed, safety, and scalability. It can be used for simple scripting or sophisticated web applications. By exposing Python as a series of simple recipes, this book gives you insight into specific language features in a particular context. Having a tangible context helps make the language or a given standard library feature easier to understand. This book comes with 133 recipes on the latest version of Python 3.8. The recipes will benefit everyone, from beginners just starting out with Python to experts. You'll not only learn Python programming concepts but also how to build complex applications. The recipes will touch upon all necessary Python concepts related to data structures, object oriented programming, functional programming, and statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively take advantage of it. By the end of this Python book, you will be equipped with knowledge of testing, web services, configuration, and application integration tips and tricks. You will be armed with the knowledge of how to create applications with flexible logging, powerful configuration, command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
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Function parameters and type hints

Python 3 added syntax for type hints. The mypy tool is one way to validate these type hints to be sure the hints and the code agree. All the examples shown in this book have been checked with the mypy tool.

This extra syntax for the hints is optional. It's not used at runtime and has no performance costs. If hints are present, tools like mypy can use them. The tool checks that the operations on the n parameter inside the function agree with the type hint about the parameter. The tool also tries to confirm that the return expressions both agree with the type hint. When an application has numerous function definitions, this extra scrutiny can be very helpful.

Getting ready

For an example of type hints, we'll look at some color computations. The first of these is extracting the Red, Green, and Blue values from the color codes commonly used in the style sheets for HTML pages. There are a variety of ways of encoding the values...