diff -r 5c091acc799f Lib/argparse.py
--- a/Lib/argparse.py	Sat Aug 17 17:25:27 2013 +0200
+++ b/Lib/argparse.py	Sat Aug 17 19:14:33 2013 +0300
@@ -1096,6 +1096,21 @@
 
         return parser
 
+    def remove_parser(self, name, **kwargs):
+        # remove choice help from list
+        if 'help' in kwargs:
+            self._choices_actions = [action
+                                     for action in self._choices_actions
+                                     if action.metavar != name]
+
+        # remove the parser from the map
+        self._name_parser_map.pop(name, None)
+
+        # remove aliases
+        aliases = kwargs.pop('aliases', ())
+        for alias in aliases:
+            self._name_parser_map.pop(alias, None)
+
     def _get_subactions(self):
         return self._choices_actions