Add support for empty string arguments and arguments that contain spaces.

2 files changed, 28 insertions, 2 deletions

diff --git a/argparse.py b/argparse.py
index 83fac14..bb641e2 100644
--- a/argparse.py
+++ b/argparse.py
@@ -1785,6 +1785,14 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
         return result

 

     def _parse_optional(self, arg_string):

+        # if it's an empty string, it was meant to be a positional

+        if not arg_string:

+            return None

+

+        # if it contains a space, it was meant to be a positional

+        if ' ' in arg_string:

+            return None

+

         # if it doesn't start with a prefix, it was meant to be positional

         if not arg_string[0] in self.prefix_chars:

             return None

diff --git a/test/test_argparse.py b/test/test_argparse.py
index ba1a3ba..dd66239 100644
--- a/test/test_argparse.py
+++ b/test/test_argparse.py
@@ -203,8 +203,9 @@ class ParserTesterMetaclass(type):
 

             def test_successes(self, tester):

                 parser = self._get_parser(tester)

-                for args_str, expected_ns in tester.successes:

-                    args = args_str.split()

+                for args, expected_ns in tester.successes:

+                    if isinstance(args, str):

+                        args = args.split()

                     result_ns = self._parse_args(parser, args)

                     tester.assertEqual(expected_ns, result_ns)

 

@@ -1045,6 +1046,23 @@ class TestOptionalsNumericAndPositionals(ParserTestCase):
     ]

 

 

+class TestEmptyAndSpaceContainingArguments(ParserTestCase):

+

+    argument_signatures = [

+        Sig('x', nargs='?'),

+        Sig('-y'),

+    ]

+    failures = ['-y']

+    successes = [

+        ([''], NS(x='', y=None)),

+        (['a badger'], NS(x='a badger', y=None)),

+        (['-a badger'], NS(x='-a badger', y=None)),

+        (['-y', ''], NS(x=None, y='')),

+        (['-y', 'a badger'], NS(x=None, y='a badger')),

+        (['-y', '-a badger'], NS(x=None, y='-a badger')),

+    ]

+

+

 class TestNargsZeroOrMore(ParserTestCase):

     """Tests specifying an args for an Optional that accepts zero or more"""