allow extra_args in applications

IPython/config/application.py

@@ -112,6 +112,9 b' class Application(SingletonConfigurable):'
     # parse_command_line will initialize a subapp, if requested
     subapp = Instance('IPython.config.application.Application', allow_none=True)
     
+    # extra command-line arguments that don't set config values
+    extra_args = List(Unicode)
+    
 
     def __init__(self, **kwargs):
         SingletonConfigurable.__init__(self, **kwargs)
@@ -266,13 +269,7 b' class Application(SingletonConfigurable):'
     
     def initialize_subcommand(self, subc, argv=None):
         """Initialize a subcommand with argv"""
-        subapp,help = self.subcommands.get(subc, (None,None))
-        if subapp is None:
-            self.print_description()
-            print "No such subcommand: %r"%subc
-            print
-            self.print_subcommands()
-            self.exit(1)
+        subapp,help = self.subcommands.get(subc)
         
         if isinstance(subapp, basestring):
             subapp = import_item(subapp)
@@ -289,7 +286,7 b' class Application(SingletonConfigurable):'
         if self.subcommands and len(argv) > 0:
             # we have subcommands, and one may have been specified
             subc, subargv = argv[0], argv[1:]
-            if re.match(r'^\w(\-?\w)*$', subc):
+            if re.match(r'^\w(\-?\w)*$', subc) and subc in self.subcommands:
                 # it's a subcommand, and *not* a flag or class parameter
                 return self.initialize_subcommand(subc, subargv)
             
@@ -312,6 +309,8 b' class Application(SingletonConfigurable):'
             self.print_help()
             self.exit(1)
         self.update_config(config)
+        # store unparsed args in extra_args
+        self.extra_args = loader.extra_args
 
     def load_config_file(self, filename, path=None):
         """Load a .py based config file by filename and path."""

IPython/config/loader.py

@@ -382,7 +382,9 b' class KeyValueConfigLoader(CommandLineConfigLoader):'
             aliases = self.aliases
         if flags is None:
             flags = self.flags
-
+        
+        self.extra_args = []
+        
         for item in argv:
             if kv_pattern.match(item):
                 lhs,rhs = item.split('=',1)
@@ -414,8 +416,13 b' class KeyValueConfigLoader(CommandLineConfigLoader):'
                         self.config[sec].update(c)
                 else:
                     raise ValueError("Invalid flag: %r"%flag)
-            else:
+            elif item.startswith('-'):
+                # this shouldn't ever be valid
                 raise ArgumentError("Invalid argument: %r"%item)
+            else:
+                # keep all args that aren't valid in a list, 
+                # in case our parent knows what to do with them.
+                self.extra_args.append(item)
         return self.config
 
 class ArgParseConfigLoader(CommandLineConfigLoader):

IPython/config/tests/test_application.py

@@ -116,14 +116,20 b' class TestApplication(TestCase):'
         """test that setting flags doesn't clobber existing settings"""
         app = MyApp()
         app.parse_command_line(["Bar.b=5", "--disable"])
-        print app.config
         app.init_bar()
         self.assertEquals(app.bar.enabled, False)
         self.assertEquals(app.bar.b, 5)
         app.parse_command_line(["--enable", "Bar.b=10"])
-        print app.config
         app.init_bar()
         self.assertEquals(app.bar.enabled, True)
         self.assertEquals(app.bar.b, 10)
     
+    def test_extra_args(self):
+        app = MyApp()
+        app.parse_command_line(['extra', "Bar.b=5", "--disable", 'args'])
+        app.init_bar()
+        self.assertEquals(app.bar.enabled, False)
+        self.assertEquals(app.bar.b, 5)
+        self.assertEquals(app.extra_args, ['extra', 'args'])
+    
 

IPython/config/tests/test_loader.py

@@ -123,6 +123,13 b' class TestKeyValueCL(TestCase):'
         self.assertEquals(config.Foo.Bar.value, 10)
         self.assertEquals(config.Foo.Bam.value, range(10))
         self.assertEquals(config.D.C.value, 'hi there')
+    
+    def test_extra_args(self):
+        cl = KeyValueConfigLoader()
+        config = cl.load_config(['a=5', 'b', 'c=10', 'd'])
+        self.assertEquals(cl.extra_args, ['b', 'd'])
+        self.assertEquals(config.a, 5)
+        self.assertEquals(config.c, 10)
 
 
 class TestConfig(TestCase):