[3.11] gh-87452: Improve the Popen.returncode docs (#103771)
Clarifies that it remains None until a method checking the child process
status has been called and noticed it has terminated.
(cherry picked from commit 68f583658247ceced323d79e1cf775c91c53c019)
Co-authored-by: Joshua Herman <30265+zitterbewegung@users.noreply.github.com>
Co-authored-by: Łukasz Langa <lukasz@langa.pl>
diff --git a/Doc/library/subprocess.rst b/Doc/library/subprocess.rst
index 63d5206..4c7fb27 100644
--- a/Doc/library/subprocess.rst
+++ b/Doc/library/subprocess.rst
@@ -921,9 +921,12 @@
.. attribute:: Popen.returncode
- The child return code, set by :meth:`poll` and :meth:`wait` (and indirectly
- by :meth:`communicate`). A ``None`` value indicates that the process
- hasn't terminated yet.
+ The child return code. Initially ``None``, :attr:`returncode` is set by
+ a call to the :meth:`poll`, :meth:`wait`, or :meth:`communicate` methods
+ if they detect that the process has terminated.
+
+ A ``None`` value indicates that the process hadn't yet terminated at the
+ time of the last method call.
A negative value ``-N`` indicates that the child was terminated by signal
``N`` (POSIX only).
