Index: Lib/argparse.py
===================================================================
--- Lib/argparse.py	(revision 87438)
+++ Lib/argparse.py	(working copy)
@@ -980,6 +980,32 @@
         parser.exit()
 
 
+class _WriteAction(Action):
+
+    def __init__(self,
+                 option_strings,
+                 message,
+                 file=None,
+                 dest=SUPPRESS,
+                 default=SUPPRESS,
+                 help=None):
+        super(_WriteAction, self).__init__(
+            option_strings=option_strings,
+            dest=dest,
+            default=default,
+            nargs=0,
+            help=help)
+        self.message = message
+        self.file = file
+
+    def __call__(self, parser, namespace, values, option_string=None):
+        if self.file is None:
+            self.file = _sys.stdout
+        self.file.write(self.message)
+        self.file.write('\n')
+        parser.exit()
+
+
 class _VersionAction(Action):
 
     def __init__(self,
@@ -1170,6 +1196,7 @@
         self.register('action', 'append_const', _AppendConstAction)
         self.register('action', 'count', _CountAction)
         self.register('action', 'help', _HelpAction)
+        self.register('action', 'write', _WriteAction)
         self.register('action', 'version', _VersionAction)
         self.register('action', 'parsers', _SubParsersAction)