Concurrency - Python News | Practical Python Engineering

13 mins read

Inside CPython Sub-Interpreters: How Immortal Objects Share Memory Without the GIL

AI/ML

April 20, 2026May 19, 2026 Priya SharmaTagged CPython internals, DuckDB python, Free threading, GIL removal, Ibis framework, Marimo notebooks, Mojo language, Polars dataframe, Python JIT, Rust Python

The technical barrier that kept Python’s sub-interpreter feature from being genuinely useful for a decade wasn’t parallelism — it was reference counting.

15 mins read

Free-Threaded Python 3.13t: Measuring Contention With perf c2c

Concurrency

April 17, 2026April 19, 2026 Priya SharmaTagged CPython internals, DuckDB python, Free threading, GIL removal, Ibis framework, Marimo notebooks, Mojo language, Polars dataframe, Python JIT, Rust Python

The first time you run a threaded dict.get loop on python3.13t and watch it scale at 1.3x on 8 cores instead of 7x, the instinct is to blame Python.

2 mins read

Python Free Threading: The End of the GIL and the Future of Parallelism

Concurrency

December 16, 2025December 27, 2025 Priya SharmaTagged Free threading

Introduction: The Fall of the Global Interpreter Lock For over two decades, the Global Interpreter Lock (GIL) has been the single most controversial.

11 mins read

Mastering Python Testing: From Static Analysis to End-to-End Automation

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November 26, 2025December 26, 2025 Nia OkoroTagged python testing

The landscape of Python development is undergoing a seismic shift. With the recent discussions surrounding CPython internals , the gradual GIL removal.