diff -r ae047ebe10f9 Lib/argparse.py
--- a/Lib/argparse.py	Wed Dec 11 17:21:13 2013 -0600
+++ b/Lib/argparse.py	Thu Dec 12 02:31:41 2013 -0800
@@ -1145,13 +1145,16 @@
             builtin open() function.
         - errors -- A string indicating how encoding and decoding errors are to
             be handled. Accepts the same value as the builtin open() function.
+        - expanduser -- A boolean specifying if os.path.expanduser should be called on the path
+            before opening
     """
 
-    def __init__(self, mode='r', bufsize=-1, encoding=None, errors=None):
+    def __init__(self, mode='r', bufsize=-1, encoding=None, errors=None, expanduser=False):
         self._mode = mode
         self._bufsize = bufsize
         self._encoding = encoding
         self._errors = errors
+        self._expanduser = expanduser
 
     def __call__(self, string):
         # the special argument "-" means sys.std{in,out}
@@ -1163,6 +1166,9 @@
             else:
                 msg = _('argument "-" with mode %r') % self._mode
                 raise ValueError(msg)
+        else:
+            if self._expanduser:
+                string = _os.path.expanduser(string)
 
         # all other arguments are used as file names
         try:
diff -r ae047ebe10f9 Lib/test/test_argparse.py
--- a/Lib/test/test_argparse.py	Wed Dec 11 17:21:13 2013 -0600
+++ b/Lib/test/test_argparse.py	Thu Dec 12 02:31:41 2013 -0800
@@ -1588,6 +1588,39 @@
                 type('foo')
                 m.assert_called_with('foo', *args)
 
+class TestFileTypeExpandUser(TestCase):
+    """ Test that tilde is expanded correctly """
+
+    def test_open_tilde(self):
+        FT = argparse.FileType
+        foo = '~/fo~o'
+        expandedfoo = os.path.expanduser(foo)
+        cases = [
+            # Expand
+            (FT('rb', expanduser=True), expandedfoo, ('rb', -1, None, None)),
+            (FT('w', 1, expanduser=True), expandedfoo, ('w', 1, None, None)),
+            (FT('w', errors='replace', expanduser=True), expandedfoo,('w', -1, None, 'replace')),
+            (FT('wb', encoding='big5', expanduser=True), expandedfoo, ('wb', -1, 'big5', None)),
+            (FT('w', 0, 'l1', 'strict', expanduser=True), expandedfoo, ('w', 0, 'l1', 'strict')),
+           # Don't expand
+            (FT('rb', expanduser=False), foo, ('rb', -1, None, None)),
+            (FT('w', 1, expanduser=False), foo, ('w', 1, None, None)),
+            (FT('w', errors='replace', expanduser=False), foo,('w', -1, None, 'replace')),
+            (FT('wb', encoding='big5', expanduser=False), foo, ('wb', -1, 'big5', None)),
+            (FT('w', 0, 'l1', 'strict', expanduser=False), foo, ('w', 0, 'l1', 'strict')),
+            # default
+            (FT('rb'), foo, ('rb', -1, None, None)),
+            (FT('w', 1), foo, ('w', 1, None, None)),
+            (FT('w', errors='replace'), foo, ('w', -1, None, 'replace')),
+            (FT('wb', encoding='big5'), foo, ('wb', -1, 'big5', None)),
+            (FT('w', 0, 'l1', 'strict'), foo, ('w', 0, 'l1', 'strict')),
+            ]
+        with mock.patch('builtins.open') as m:
+            for type, targetfilename, args in cases:
+                type(foo)
+                m.assert_called_with(targetfilename, *args)
+
+
 
 class TestTypeCallable(ParserTestCase):
     """Test some callables as option/argument types"""