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

Avoiding a potential problem with break statements

The common way to understand a for statement is that it creates a for all condition. At the end of the statement, we can assert that, for all items in a collection, some processing has been done.

This isn't the only meaning for a for statement. When we introduce the break statement inside the body of a for, we change the semantics to there exists. When the break statement leaves the for (or while) statement, we can assert only that there exists at least one item that caused the statement to end.

There's a side issue here. What if the for statement ends without executing break? Either way, we're at the statement after the for statement.

The condition that's true upon leaving a for or while statement with a break can be ambiguous. Did it end normally? Did it execute break? We can't easily tell, so we'll provide a recipe that gives us some design guidance.

This can become an even bigger...