At first I thought that this wasn't valid Python code. However, it turns out that this code runs perfectly fine in PyPy but not in CPython. CPython has since forever required that "sort() accepts two ...

Official support for free-threaded Python, and free-threaded improvements Python’s free-threaded build promises true parallelism for threads in Python programs by removing the Global Interpreter Lock ...

I ran into a case where pypy performs worse and worse as the input data length increases, compare to cpython. I typically expect the opposite, since pypy performance is supposed to be more apparent ...