diff options
| -rw-r--r-- | Doc/library/argparse.rst | 9 | ||||
| -rw-r--r-- | Lib/argparse.py | 7 | ||||
| -rw-r--r-- | Lib/test/test_argparse.py | 9 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Library/2019-05-14-05-38-22.bpo-23378.R25teI.rst | 1 |
4 files changed, 26 insertions, 0 deletions
diff --git a/Doc/library/argparse.rst b/Doc/library/argparse.rst index cef197f..b77a38c 100644 --- a/Doc/library/argparse.rst +++ b/Doc/library/argparse.rst @@ -797,6 +797,15 @@ how the command-line arguments should be handled. The supplied actions are: >>> parser.parse_args(['--version']) PROG 2.0 +* ``'extend'`` - This stores a list, and extends each argument value to the + list. + Example usage:: + + >>> parser = argparse.ArgumentParser() + >>> parser.add_argument("--foo", action="extend", nargs="+", type=str) + >>> parser.parse_args(["--foo", "f1", "--foo", "f2", "f3", "f4"]) + Namespace(foo=['f1', 'f2', 'f3', 'f4']) + You may also specify an arbitrary action by passing an Action subclass or other object that implements the same interface. The recommended way to do this is to extend :class:`Action`, overriding the ``__call__`` method 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 @@ class _SubParsersAction(Action): 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 @@ class _ActionsContainer(object): 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() diff --git a/Lib/test/test_argparse.py b/Lib/test/test_argparse.py index e849c7b..9d68f40 100644 --- a/Lib/test/test_argparse.py +++ b/Lib/test/test_argparse.py @@ -1786,6 +1786,15 @@ class TestActionRegistration(TestCase): self.assertEqual(parser.parse_args(['42']), NS(badger='foo[42]')) +class TestActionExtend(ParserTestCase): + argument_signatures = [ + Sig('--foo', action="extend", nargs="+", type=str), + ] + failures = () + successes = [ + ('--foo f1 --foo f2 f3 f4', NS(foo=['f1', 'f2', 'f3', 'f4'])), + ] + # ================ # Subparsers tests # ================ diff --git a/Misc/NEWS.d/next/Library/2019-05-14-05-38-22.bpo-23378.R25teI.rst b/Misc/NEWS.d/next/Library/2019-05-14-05-38-22.bpo-23378.R25teI.rst new file mode 100644 index 0000000..c7c3f17 --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-05-14-05-38-22.bpo-23378.R25teI.rst @@ -0,0 +1 @@ +Add an extend action to argparser. |