Book Image

Modern Python Cookbook

Book Image

Modern Python Cookbook

Overview of this book

Python is the preferred choice of developers, engineers, data scientists, and hobbyists everywhere. It is a great scripting language that can power your applications and provide great speed, safety, and scalability. By exposing Python as a series of simple recipes, you can gain insight into specific language features in a particular context. Having a tangible context helps make the language or standard library feature easier to understand. This book comes with over 100 recipes on the latest version of Python. The recipes will benefit everyone ranging from beginner to an expert. The book is broken down into 13 chapters that build from simple language concepts to more complex applications of the language. The recipes will touch upon all the necessary Python concepts related to data structures, OOP, functional programming, as well as statistical programming. You will get acquainted with the nuances of Python syntax and how to effectively use the advantages that it offers. You will end the book equipped with the knowledge of testing, web services, and configuration and application integration tips and tricks. The recipes take a problem-solution approach to resolve issues commonly faced by Python programmers across the globe. You will be armed with the knowledge of creating applications with flexible logging, powerful configuration, and command-line options, automated unit tests, and good documentation.
Table of Contents (18 chapters)
Title Page
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

Understanding variables, references, and assignment


How do variables really work? What happens when we assign a mutable object to two variables? We can easily have two variables that share references to a common object; this can lead to potentially confusing results when the shared object is mutable. The rules are simple and the consequences are generally obvious.

We'll focus on this rule: Python shares references. It doesn't copy data.

We need to look at what this rule on reference sharing means.

We'll create two data structures, one is mutable and one is immutable. We'll use two kinds of sequences, although we could do something similar with two kinds of sets: Getting ready We'll create two data structures, one is mutable and one is immutable. We'll use two kinds of sequences, although we could do something similar with two kinds of sets:

>>> mutable = [1, 1, 2, 3, 5, 8]>>> immutable = (5, 8, 13, 21)

The mutable data structure can be changed and shared. The immutable data...