Index: Lib/optparse.py
===================================================================
--- Lib/optparse.py	(révision 87460)
+++ Lib/optparse.py	(copie de travail)
@@ -86,10 +86,16 @@
 #   Id: errors.py 509 2006-04-20 00:58:24Z gward
 
 try:
-    from gettext import gettext
+    from gettext import gettext, ngettext
 except ImportError:
     def gettext(message):
         return message
+
+    def ngettext(singular, plural, n):
+        if n == 1:
+            return singular
+        return plural
+
 _ = gettext
 
 
@@ -1479,10 +1485,10 @@
             nargs = option.nargs
             if len(rargs) < nargs:
                 if nargs == 1:
-                    self.error(_("%s option requires an argument") % opt)
-                else:
-                    self.error(_("%s option requires %d arguments")
-                               % (opt, nargs))
+                self.error(ngettext(
+                    "%(option)s option requires %(number)d argument",
+                    "%(option)s option requires %(number)d arguments",
+                    nargs) % (opt, nargs))
             elif nargs == 1:
                 value = rargs.pop(0)
             else:
@@ -1518,10 +1524,10 @@
                 nargs = option.nargs
                 if len(rargs) < nargs:
                     if nargs == 1:
-                        self.error(_("%s option requires an argument") % opt)
-                    else:
-                        self.error(_("%s option requires %d arguments")
-                                   % (opt, nargs))
+                        self.error(ngettext(
+                            "%(option)s option requires %(number)d argument",
+                            "%(option)s option requires %(number)d arguments",
+                            nargs) % (opt, nargs))
                 elif nargs == 1:
                     value = rargs.pop(0)
                 else: