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

Using the Windows Python launcher


Starting with version 3.3, Python defaults to installing the Python launcher when installing the rest of the language. The launcher allows Python scripts or the Windows command-line to specify a particular Python version and will locate and launch that version.

While installed with v3.3 or later, the launcher is compatible with all versions of Python. The Python launcher will select the most appropriate version of Python for the script and will use per-user Python installations rather than all-user installs.

How to do it...

  1. To check that the launcher is installed, simply type py on the Windows Command Prompt. If installed, the latest version of Python is launched.
  2. If not installed, you will receive the following error:
      'py' is not recognized as an internal or external command, 
      operable program or batch file.
  1. Assuming different versions of Python are installed, to use a different version simply indicate it via a - option:
      py -2.6 # Launches Python...