[Python-checkins] bpo-26510: Add versionchanged for required arg of add_subparsers (GH-16588)

Sun Oct 6 22:08:55 EDT 2019

https://github.com/python/cpython/commit/9e71917e0290972f65711f75510078f799cf0b59
commit: 9e71917e0290972f65711f75510078f799cf0b59
branch: master
author: Adam J. Stewart <ajstewart426 at gmail.com>
committer: Miss Islington (bot) <31488909+miss-islington at users.noreply.github.com>
date: 2019年10月06日T19:08:48-07:00
summary:
 bpo-26510: Add versionchanged for required arg of add_subparsers (GH-16588)
The `required` argument to `argparse.add_subparsers` was added in #3027. This PR specifies the earliest version of Python where it is available.
https://bugs.python.org/issue26510
Automerge-Triggered-By: @merwok
files:
M Doc/library/argparse.rst
M Doc/whatsnew/3.7.rst

diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst
index a8aeca41a70a6..00115d5cd1e9b 100644
--- a/Doc/library/argparse.rst
+++ b/Doc/library/argparse.rst
@@ -1636,7 +1636,7 @@ Sub-commands
 stored; by default ``None`` and no value is stored
 
 * required_ - Whether or not a subcommand must be provided, by default
- ``False``.
+ ``False`` (added in 3.7)
 
 * help_ - help for sub-parser group in help output, by default ``None``
 
@@ -1792,6 +1792,9 @@ Sub-commands
 >>> parser.parse_args(['2', 'frobble'])
 Namespace(subparser_name='2', y='frobble')
 
+ .. versionchanged:: 3.7
+ New *required* keyword argument.
+
 
 FileType objects
 ^^^^^^^^^^^^^^^^
diff --git a/Doc/whatsnew/3.7.rst b/Doc/whatsnew/3.7.rst
index af7e22d9faa9e..1ec8e0c04c76b 100644
--- a/Doc/whatsnew/3.7.rst
+++ b/Doc/whatsnew/3.7.rst
@@ -2401,6 +2401,10 @@ Changes in the Python API
 instead of a :class:`bytes` instance.
 (Contributed by Victor Stinner in :issue:`21071`.)
 
+* :mod:`argparse` subparsers can now be made mandatory by passing ``required=True``
+ to :meth:`ArgumentParser.add_subparsers() <argparse.ArgumentParser.add_subparsers>`.
+ (Contributed by Anthony Sottile in :issue:`26510`.)
+
 * :meth:`ast.literal_eval()` is now stricter. Addition and subtraction of
 arbitrary numbers are no longer allowed.
 (Contributed by Serhiy Storchaka in :issue:`31778`.)
