We can only protect people from themselves so much - "shell=True" is invaluable when you actually want to invoke the shell, and the shell has much better tools for process invocation and pipeline processing than Python does (since shells are, in effect, domain specific languages dedicated to those tasks).

If someone is blindly copying and pasting code from the internet, then shell injection attacks are likely to be the *least* of the security problems in anything they're building.

The point of the examples is to demonstrate the return code handling and using the shell is the easiest way to do that. I'll add a note to the docstrings to be aware of the security issues with the parameter, though.

As far as the keyword arguments go, no, I can't just drop the bare '*' from the abbreviated signature, because that would be making claims about the signature that are just plain *wrong* (there are other positional arguments that appear before 'stdin'). I'll add a note explaining that point somewhere in the 2.7 version, though.