Thanks for the patch, Tim.

> Changed true -> :const:`True` in subprocess.rst.

This is out of scope for this issue and I actually prefer the current form.

Having method and class signatures in subprocess.__doc__ would make it less maintainable. I'd prefer having a short docstring that describes what the modules does, and what its modern API look like.

I don't think we should duplicate documentation of CalledProcessError, TimeoutExpired and Popen in their docstrings. Perhaps it would be better to just document which parameters are POSIX only.

Also, did you use the GitHub mirror to create the patch? If so, please use the official Mercurial repository: https://docs.python.org/devguide/setup.html#checkout Rietveld doesn't like patches created from the git repository so it was a bit hard to review the patch without using Rietveld. Thanks!