Book Image

Secret Recipes of the Python Ninja

Book Image

Secret Recipes of the Python Ninja

Overview of this book

This book covers the unexplored secrets of Python, delve into its depths, and uncover its mysteries. You’ll unearth secrets related to the implementation of the standard library, by looking at how modules actually work. You’ll understand the implementation of collections, decimals, and fraction modules. If you haven’t used decorators, coroutines, and generator functions much before, as you make your way through the recipes, you’ll learn what you’ve been missing out on. We’ll cover internal special methods in detail, so you understand what they are and how they can be used to improve the engineering decisions you make. Next, you’ll explore the CPython interpreter, which is a treasure trove of secret hacks that not many programmers are aware of. We’ll take you through the depths of the PyPy project, where you’ll come across several exciting ways that you can improve speed and concurrency. Finally, we’ll take time to explore the PEPs of the latest versions to discover some interesting hacks.
Table of Contents (17 chapters)
Title Page
Copyright and Credits
Packt Upsell
Foreword
Contributors
Preface
Index

PEP 554 – Multiple subinterpreters


PEP 554 was created in September, 2017, and is currently in Draft status. It is projected for inclusion in Python v3.8. This PEP discusses the potential of creating an interpreters module, allowing access to multiple interpreters within the same process.

Multiple interpreters, also known as subinterpreters, have been a feature of Python since version 1.5. While most developers are aware of the normal Python interpreter, either through the interactive Python console or simply by executing code, there is the ability to support multiple, independent interpreters within the same process, and, if needed, within the same thread. The subinterpreters can be switched between by using the PyThreadState_Swap() function.

Each subinterpreter is a nearly complete, separate Python environment for code execution. Each interpreter has separate and independent versions of all import modules, system paths, and even STDIN, STDOUT, and STDERR streams. Extension modules can be...