[docs] Docstring of the subprocess module should be cleaned up (issue 26240)

[vadmium+py at gmail.com]

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py
File Lib/subprocess.py (left):

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#oldcode220
Lib/subprocess.py:220: Check if child process has terminated.  Returns
returncode
This could be moved a docstring for the actual poll() method

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#oldcode239
Lib/subprocess.py:239: The following attributes are also available:
Maybe these should be mentioned in the Popen docstring

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py
File Lib/subprocess.py (right):

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#newcode37
Lib/subprocess.py:37: check_output(...): Same as check_call but returns
the contents of
Round brackets for check_call(), for consistency with above?

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#newcode550
Lib/subprocess.py:550: bufsize: negative io buffer size. 0 for
unbuffered, 1 for line buffered
I don’t understand this. Perhaps you mean a negative value is translated
to the default io module buffer size? Or clarify this buffer size is
specifically for pipes?

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#newcode555
Lib/subprocess.py:555: input, standard output and standard error file
handles, respectively.
Might be worth listing PIPE, DEVNULL, STDOUT

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#newcode571
Lib/subprocess.py:571: startupinfo and creationflags: (Windows only)
These colons should be dropped I think, i.e.

startupinfo and creationflags (Windows only)
restore_signals (POSIX only)
etc

https://bugs.python.org/review/26240/diff/18897/Lib/subprocess.py#newcode580
Lib/subprocess.py:580: file objects stdin, stdout and stderr.
inconsistent indentation

https://bugs.python.org/review/26240/