Python Descriptors: Understanding and Using the Descriptor Protocol

Description

Create descriptors and see ideas and examples of how to use descriptors effectively. In this short book, you’ll explore descriptors in general, with a deep explanation of what descriptors are, how they work, and how they're used. Once you understand the simplicity of the descriptor protocol, the author delves into using and creating descriptors in practice, with plenty of tips, patterns, and real-world guidance. Because descriptors are inherently flexible, you’ll work with multiple examples illustrating how to best take advantage of them. This second edition includes additions throughout, including new material covering the set_name_() descriptors, new and improved flowcharts to explain the inner workings of descriptors, and a completely new chapter to address instance-level attributes, the easiest way to create descriptors correctly the first time. Although brief, Python Descriptors is a comprehensive guide to creating Python descriptors, including a pip install-able library called descriptor_tools, which was written alongside this book and is an open source library on GitHub. After reading this book, you will have a solid understanding of how descriptors work and the techniques to avoid the big gotchas associated with working with them. What You Will Learn ● Discover descriptor protocols ● Master attribute access and how it applies to descriptors ● Build your own descriptors ● Use descriptors to store attributes ● Create read-only descriptors ● Explore the descriptor classes ● Apply the other uses of descriptors Who This Book Is For Experienced Python coders, programmers, and developers. Front Matter ....Pages i-xiv Front Matter ....Pages 1-1 What Is a Descriptor? (Jacob Zimmerman)....Pages 3-5 The Descriptor Protocol (Jacob Zimmerman)....Pages 7-10 What Are Descriptors Good For? (Jacob Zimmerman)....Pages 11-14 Descriptors in the Standard Library (Jacob Zimmerman)....Pages 15-20 Attribute Access and Descriptors (Jacob Zimmerman)....Pages 21-28 Front Matter ....Pages 29-29 Which Methods Are Needed? (Jacob Zimmerman)....Pages 31-37 Storing the Attributes (Jacob Zimmerman)....Pages 39-57 Read-Only Descriptors (Jacob Zimmerman)....Pages 59-65 Writing__delete__ (Jacob Zimmerman)....Pages 67-68 Descriptors Are Classes Too (Jacob Zimmerman)....Pages 69-72 Reusing the Wheel (Jacob Zimmerman)....Pages 73-80 Instance-Level Descriptors (Jacob Zimmerman)....Pages 81-88 Other Uses of Descriptors In the World (Jacob Zimmerman)....Pages 89-91 Back Matter ....Pages 93-97