​​CPython Guide

​​Introduction

​​This guide is a compilation of many sources of knowledge. I've watched countlesss
​​videos on YouTube of professors and past PyCon talks, read endless documentation
​​and blog posts, and written hundreds of print statements to track the process of
​​CPython's execution (which I highly recommend doing). These experiences have
​​highly influenced my approach to this document, as well as having provided me
​​with a solid foundation to jump in to CPython's source code with two feet.

​​Who is this guide for?

​​Ultimately, this guide is for anyone with a desire to contribute to CPython or anyone
​​who wants to learn more about how Python works. That said, there may be sections that
​​require additional knowledge or skill sets. For example, if you wish to contribute to
​​the C portions of Python, I would highly recommend a primer on C.

​​What this guide will cover

​​This guide will cover
  • ​​Basics of writing a language (VERY high level)
  • ​​How the parser works (+)
  • ​​How to define an object type (or is this in the C/API docs already?) (+)
  • ​​Tools and Common Patterns
  • ​​Lesser known C Patterns used (+)
  • ​​Python conventions
  • ​​Overview of code structure (important directories, what they do)
  • ​​Overview of Python's Interpreter
  • ​​Bytecode*
  • ​​Reference counting*
  • ​​Overview of code interactions/flow (who calls what, what compiles what, etc)
  • ​​Tools and tricks for learning
  • ​​Modules (e.g. dis, .func_cod)
  • ​​Strategies
  • ​​How to find the definition of something (+)
  • ​​How to find where a given error comes from (+)
  • ​​TAGS
  • ​​Tips for contributing
  • ​​Additional random topics
  • ​​The GIL (Larry's Gilectomy notwithstanding)
  • ​​Open hashing
  • ​​Low-level memory allocation
  • ​​Memory locality
  • ​​How to handle errors (e.g. when to use a goto, making sure you deref appropriately)
  • ​​Sources
  • ​​Further reading

​​What this guide WON'T cover

​​This guide will not cover anything that is included in the Python Dev Guide <https://docs.python.org/devguide/>​_, as that guide is extremely well written and maintained.
​​Topics that I find particularly useful from the Dev Guide include:
​​Quick Start <https://docs.python.org/devguide/index.html#quick-start>​_
​​Contributing <https://docs.python.org/devguide/index.html#contributing>​_
​​Writing and Running Tests <https://docs.python.org/devguide/runtests.html>​_
​​Documenting Python <https://docs.python.org/devguide/documenting.html>​_
​​Working wtih Mercurial <https://docs.python.org/devguide/committing.html#working-with-mercurial>​_ and Mercurial for git developers <https://docs.python.org/devguide/gitdevs.html>​_
​​Development Cycle <https://docs.python.org/devguide/devcycle.html>​_