Python 3.13.1 Released November 2025 Online

import interpreters import math import time def mandel_chunk(x_min, x_max, y_min, y_max, width, height): # ... intense fractal math ... return pixels

She typed:

Elena’s own company, a fintech startup that processed real-time currency trades, had a twenty-thousand-line module written by a long-departed genius who had assumed, incorrectly, that list.append was safe across threads because “the GIL will save us.” python 3.13.1 released november 2025

The CPU graph on her system monitor exploded into four perfect, separate columns—each core pegged at 98%, none waiting, none blocking. The script finished in 2.1 seconds. The single-threaded version? 7.4 seconds. separate columns—each core pegged at 98%

futures = [] with interp1.run() as i1: futures.append(i1.call(mandel_chunk, (-2.0, -1.0, -1.5, 0.0, 500, 500))) # ... repeat for four interpreters ... python 3.13.1 released november 2025