It's part of a larger effort to bring the capabilities of extension modules up to par with Python ones. For example, it's one less surprise you'd get when you Cythonize a module. And it's not only for stdlib modules – it's for any extension module.



I'd be happy to answer questions here. But to get up to speed and avoid bpo comment lag, you can also see the current discussion on import-sig [0], or dig up some of the older conversations there leading up to PEP 489 (Feb-May 2015). And if you're at PyCon, you could have a high-bandwidth conversation with Nick Coghlan – he has the master plan in his head :)

[0] https://mail.python.org/pipermail/import-sig/2017-May/001072.html