[Python-checkins] bpo-31065: Add doc about Popen.poll returning None. (#3169)

[Gregory P. Smith]

https://github.com/python/cpython/commit/006617ff7d6df3fdedcfe53e94ee2c52cc796437
commit: 006617ff7d6df3fdedcfe53e94ee2c52cc796437
branch: master
author: Ivan Chernoff <chernoffivan at gmail.com>
committer: Gregory P. Smith <greg at krypto.org>
date: 2017-08-29T07:46:24-07:00
summary:

bpo-31065: Add doc about Popen.poll returning None. (#3169)

files:
M Doc/library/subprocess.rst

diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 2eaa48e070d..a4e234e62ae 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -584,7 +584,7 @@ Instances of the :class:`Popen` class have the following methods:
 .. method:: Popen.poll()
 
    Check if child process has terminated.  Set and return
-   :attr:`~Popen.returncode` attribute.
+   :attr:`~Popen.returncode` attribute. Otherwise, returns ``None``.
 
 
 .. method:: Popen.wait(timeout=None)