commit aa32a7e1116f7aaaef9fec453db910e90ab7b101
author Batuhan Taşkaya <47358913+isidentical@users.noreply.github.com> Tue May 21 20:47:42 2019 +0300
committer Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> Tue May 21 10:47:42 2019 -0700
tree 2e361b8ada3bdcaac42a8aa0e237baaf814d66c9
parent d5c120f7eb6f2a9cdab282a5d588afed307a23df

bpo-23378: Add an extend action to argparse (GH-13305)



Add an extend action to argparse


https://bugs.python.org/issue23378

Lib/argparse.py

diff --git a/Lib/argparse.py b/Lib/argparse.py
index 798766f..ef888f0 100644
--- a/Lib/argparse.py
+++ b/Lib/argparse.py
@@ -1154,6 +1154,12 @@
             vars(namespace).setdefault(_UNRECOGNIZED_ARGS_ATTR, [])
             getattr(namespace, _UNRECOGNIZED_ARGS_ATTR).extend(arg_strings)
 
+class _ExtendAction(_AppendAction):
+    def __call__(self, parser, namespace, values, option_string=None):
+        items = getattr(namespace, self.dest, None)
+        items = _copy_items(items)
+        items.extend(values)
+        setattr(namespace, self.dest, items)
 
 # ==============
 # Type classes
@@ -1262,6 +1268,7 @@
         self.register('action', 'help', _HelpAction)
         self.register('action', 'version', _VersionAction)
         self.register('action', 'parsers', _SubParsersAction)
+        self.register('action', 'extend', _ExtendAction)
 
         # raise an exception if the conflict handler is invalid
         self._get_handler()