--- /usr/lib/python3.2/argparse.py	2011-02-20 19:43:31.000000000 +0100
+++ argparse.py	2011-02-28 17:39:56.000000000 +0100
@@ -586,6 +586,12 @@
             result = '...'
         elif action.nargs == PARSER:
             result = '%s ...' % get_metavar(1)
+        elif type(action.nargs) is tuple:
+            lo, hi = action.nargs
+            if hi is None:
+                result = '%d...' % lo
+            else:
+                result = '%d..%d' % action.nargs
         else:
             formats = ['%s' for _ in range(action.nargs)]
             result = ' '.join(formats) % get_metavar(action.nargs)
@@ -1424,8 +1430,65 @@
                 raise ValueError(msg % option_string)
             dest = dest.replace('-', '_')
 
+        # preprocess nargs
+        nargs = kwargs.pop('nargs', None)
+        if nargs is not None:
+            if type(nargs) in [tuple, list]:
+                # allowed inputs:
+                # - (lo, hi, ...)
+                # - (None, hi, ...)
+                # - (lo, None, ...)
+                # - (None, None, ...)
+                # 
+                # ouput:
+                # - (lo, hi)
+                # - (lo, None)
+                # - ?, *, + or int
+                try:
+                    lo, hi, *tail = nargs
+
+                    if lo is not None:
+                        lo = int(lo)
+                        assert lo >= 0
+                    else:
+                        lo = 0
+
+                    if hi is not None:
+                        hi = int(hi)
+                        assert hi >= 0
+
+                except (ValueError, TypeError, AssertionError):
+                    msg = _('if nargs= is sequence, then [number, number] or [number, None] is required')
+                    raise ValueError(msg)
+
+                if hi is None:
+                    # cases (lo, None) and (0, None)
+                    if lo == 0:
+                        nargs = ZERO_OR_MORE
+                    elif lo == 1:
+                        nargs = ONE_OR_MORE
+                    else:
+                        nargs = (lo, None)
+                else:
+                    # cases (lo, hi) and (0, hi)
+                    if lo == hi:
+                        nargs = lo
+                    elif lo < hi:
+                        if lo == 0 and hi == 1:
+                            nargs = OPTIONAL
+                        else:
+                            nargs = (lo, hi)
+                    else:
+                        msg = _("nargs= lower bound %d must not be greater then upper bound %d" % (lo, hi))
+                        raise ValueError(msg)
+            else:
+                pass # do not touch other values
+
         # return the updated keyword arguments
-        return dict(kwargs, dest=dest, option_strings=option_strings)
+        if nargs is not None:
+            return dict(kwargs, dest=dest, nargs=nargs, option_strings=option_strings)
+        else:
+            return dict(kwargs, dest=dest, option_strings=option_strings)
 
     def _pop_action_class(self, kwargs, default=None):
         action = kwargs.pop('action', default)
@@ -2015,10 +2078,18 @@
                 OPTIONAL: _('expected at most one argument'),
                 ONE_OR_MORE: _('expected at least one argument'),
             }
-            default = ngettext('expected %s argument',
-                               'expected %s arguments',
-                               action.nargs) % action.nargs
-            msg = nargs_errors.get(action.nargs, default)
+
+            if type(action.nargs) is tuple:
+                lo, hi = action.nargs
+                if hi is None:
+                    msg = _('expected at least %d argument(s)' % lo)
+                else:
+                    msg = _('expected from %d to %d argument(s)' % action.nargs)
+            else:
+                default = ngettext('expected %s argument',
+                                   'expected %s arguments',
+                                   action.nargs) % action.nargs
+                msg = nargs_errors.get(action.nargs, default)
             raise ArgumentError(action, msg)
 
         # return the number of arguments matched
@@ -2171,6 +2242,14 @@
         elif nargs == PARSER:
             nargs_pattern = '(-*A[-AO]*)'
 
+        # allow lo .. hi options
+        elif type(nargs) is tuple:
+            lo, hi = nargs
+            if hi is None:
+                nargs_pattern = '(-*A{%d,})' % (lo)
+            else:
+                nargs_pattern = '(-*A{%d,%d})' % nargs
+
         # all others should be integers
         else:
             nargs_pattern = '(-*%s-*)' % '-*'.join('A' * nargs)