The CPython code base is constantly changing and evolving. Here’s a sample of references about CPython’s architecture aimed at building your understanding of CPython internals and its evolution:
Current references
Title
Brief
Author
Version
Docs on CPython internals maintained in the source tree
A guide from parser to objects, observed using GDB
Code walk from Parser, AST, Sym Table and Objects
Louie Lu
3.7.a0
The missing Python AST docs
Thomas Kluyver
3.6
Yet another guided tour of CPython
A guide for how CPython REPL works
Guido van Rossum
3.5
Python Asynchronous I/O Walkthrough
How CPython async I/O, generator and coroutine works
Philip Guo
3.5
Coding Patterns for Python Extensions
Reliable patterns of coding Python Extensions in C
Paul Ross
3.9+
Your Guide to the CPython Source Code
Your Guide to the CPython Source Code
Anthony Shaw
3.8
Historical references
Title
Brief
Author
Version
ceval, objects, pystate and miscellaneous topics
Yaniv Aknin
3.1
Eli Bendersky’s Python Internals
Objects, Symbol tables and miscellaneous topics
Eli Bendersky
3.x
A guide from parser to objects, observed using Eclipse
Code walk from Parser, AST, Sym Table and Objects
Prashanth Raghu
2.7.12
CPython internals: A ten-hour codewalk through the Python interpreter source code
Code walk from source code to generators
Philip Guo
2.7.8