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)
16
Other Books You May Enjoy
17
Index

Designing complex if...elif chains

In most cases, our scripts will involve a number of choices. Sometimes the choices are simple, and we can judge the quality of the design with a glance at the code. In other cases, the choices are more complex, and it's not easy to determine whether or not our if statements are designed properly to handle all of the conditions.

In the simplest case, we have one condition, C, and its inverse, ¬C` . These are the two conditions for an if...else statement. One condition, C, is stated in the if clause, the other condition, C's inverse, is implied in else.

This is the Law of the Excluded Middle: we're claiming there's no missing alternative between the two conditions, C and ¬C. For a complex condition, though, this isn't always true.

If we have something like:

if weather == RAIN and plan == GO_OUT:
    bring("umbrella")
else:
    bring("sunglasses")

It may not be immediately...