Add support for nargs='...', which allows emulation of command lines like "python [options] file [arguments]".

2 files changed, 30 insertions, 5 deletions

diff --git a/argparse.py b/argparse.py
index f29b6e0..16a778f 100644
--- a/argparse.py
+++ b/argparse.py
@@ -137,7 +137,8 @@ SUPPRESS = '==SUPPRESS=='
 OPTIONAL = '?'
 ZERO_OR_MORE = '*'
 ONE_OR_MORE = '+'
-PARSER = '==PARSER=='
+PARSER = 'A...'
+REMAINDER = '...'
 
 # =============================
 # Utility functions and classes
@@ -606,7 +607,9 @@ class HelpFormatter(object):
             result = '[%s [%s ...]]' % get_metavar(2)
         elif action.nargs == ONE_OR_MORE:
             result = '%s [%s ...]' % get_metavar(2)
-        elif action.nargs is PARSER:
+        elif action.nargs == REMAINDER:
+            result = '...'
+        elif action.nargs == PARSER:
             result = '%s ...' % get_metavar(1)
         else:
             formats = ['%s' for _ in range(action.nargs)]
@@ -1255,6 +1258,7 @@ class _ActionsContainer(object):
                 return action.default
         return self._defaults.get(dest, None)
 
+
     # =======================
     # Adding argument actions
     # =======================
@@ -2129,8 +2133,12 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
         elif nargs == ONE_OR_MORE:
             nargs_pattern = '(-*A[A-]*)'
 
+        # allow any number of options or arguments
+        elif nargs == REMAINDER:
+            nargs_pattern = '([-AO]*)'
+
         # allow one argument followed by any number of options or arguments
-        elif nargs is PARSER:
+        elif nargs == PARSER:
             nargs_pattern = '(-*A[-AO]*)'
 
         # all others should be integers
@@ -2150,7 +2158,7 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
     # ========================
     def _get_values(self, action, arg_strings):
         # for everything but PARSER args, strip out '--'
-        if action.nargs is not PARSER:
+        if action.nargs not in [PARSER, REMAINDER]:
             arg_strings = [s for s in arg_strings if s != '--']
 
         # optional argument produces a default when not present
@@ -2179,8 +2187,12 @@ class ArgumentParser(_AttributeHolder, _ActionsContainer):
             value = self._get_value(action, arg_string)
             self._check_value(action, value)
 
+        # REMAINDER arguments convert all values, checking none
+        elif action.nargs == REMAINDER:
+            value = [self._get_value(action, v) for v in arg_strings]
+
         # PARSER arguments convert all values, but check only the first
-        elif action.nargs is PARSER:
+        elif action.nargs == PARSER:
             value = [self._get_value(action, v) for v in arg_strings]
             self._check_value(action, value[0])
 
diff --git a/test/test_argparse.py b/test/test_argparse.py
index fadc1af..2356389 100644
--- a/test/test_argparse.py
+++ b/test/test_argparse.py
@@ -1173,6 +1173,19 @@ class TestNargsZeroOrMore(ParserTestCase):
     ]
 
 
+class TestNargsRemainder(ParserTestCase):
+    """Tests specifying a positional with nargs=REMAINDER"""
+
+    argument_signatures = [Sig('x'), Sig('y', nargs='...'), Sig('-z')]
+    failures = ['', '-z', '-z Z']
+    successes = [
+        ('X', NS(x='X', y=[], z=None)),
+        ('-z Z X', NS(x='X', y=[], z='Z')),
+        ('X A B -z Z', NS(x='X', y=['A', 'B', '-z', 'Z'], z=None)),
+        ('X Y --foo', NS(x='X', y=['Y', '--foo'], z=None)),
+    ]
+
+
 class TestOptionLike(ParserTestCase):
     """Tests options that may or may not be arguments"""