[Python-checkins] bpo-37353: Updated parser note about source code compatibility(GH-14277)

[Miss Islington (bot)]

https://github.com/python/cpython/commit/0ab6b01820afef44beea8158ba08b6469bf264a0
commit: 0ab6b01820afef44beea8158ba08b6469bf264a0
branch: 3.8
author: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
committer: GitHub <noreply at github.com>
date: 2019-09-20T07:03:21-07:00
summary:

bpo-37353: Updated parser note about source code compatibility(GH-14277)

(cherry picked from commit 062cfe3b11c61d03ccc2915e360f9b0d80e23642)

Co-authored-by: Prateek Nayak <45075669+Kriyszig at users.noreply.github.com>

files:
M Doc/library/parser.rst

diff --git a/Doc/library/parser.rst b/Doc/library/parser.rst
index a302681eca05..1d2da300709c 100644
--- a/Doc/library/parser.rst
+++ b/Doc/library/parser.rst
@@ -51,7 +51,8 @@ Python version to another as source text will always allow correct parse trees
 to be created in the target version, with the only restriction being that
 migrating to an older version of the interpreter will not support more recent
 language constructs.  The parse trees are not typically compatible from one
-version to another, whereas source code has always been forward-compatible.
+version to another, though source code has usually been forward-compatible within
+a major release series.
 
 Each element of the sequences returned by :func:`st2list` or :func:`st2tuple`
 has a simple form.  Sequences representing non-terminal elements in the grammar