It's not universally supported by all packages, for instance C-based packages will not work, more info about it here: https://pypy.org/posts/2018/09/inside-cpye

It's not universally supported by all packages, for instance C-based packages will not work, more info about it here: https://pypy.org/posts/2018/09/inside-cpyext-why-emulating-cpython-c-8083064623681286567.html https://pypy.org/posts/2018/09/inside-cpyext-why-emulating-c... With that being said, when it works, it works great but you have to evaluate whether it's suitable on a per-project/script basis.