diff -r 967f368b7f75 Objects/bytearrayobject.c
--- a/Objects/bytearrayobject.c	Sun Jan 19 00:38:36 2014 +0200
+++ b/Objects/bytearrayobject.c	Tue Jan 21 01:13:17 2014 +0200
@@ -2825,14 +2825,13 @@
     {"append", (PyCFunction)bytearray_append, METH_O, append__doc__},
     {"capitalize", (PyCFunction)stringlib_capitalize, METH_NOARGS,
      _Py_capitalize__doc__},
-    {"center", (PyCFunction)stringlib_center, METH_VARARGS, center__doc__},
+    STRINGLIB_CENTER_METHODDEF
     {"clear", (PyCFunction)bytearray_clear, METH_NOARGS, clear__doc__},
     {"copy", (PyCFunction)bytearray_copy, METH_NOARGS, copy__doc__},
     {"count", (PyCFunction)bytearray_count, METH_VARARGS, count__doc__},
     {"decode", (PyCFunction)bytearray_decode, METH_VARARGS | METH_KEYWORDS, decode_doc},
     {"endswith", (PyCFunction)bytearray_endswith, METH_VARARGS, endswith__doc__},
-    {"expandtabs", (PyCFunction)stringlib_expandtabs, METH_VARARGS | METH_KEYWORDS,
-     expandtabs__doc__},
+    STRINGLIB_EXPANDTABS_METHODDEF
     {"extend", (PyCFunction)bytearray_extend, METH_O, extend__doc__},
     {"find", (PyCFunction)bytearray_find, METH_VARARGS, find__doc__},
     {"fromhex", (PyCFunction)bytearray_fromhex, METH_VARARGS|METH_CLASS,
@@ -2854,7 +2853,7 @@
     {"isupper", (PyCFunction)stringlib_isupper, METH_NOARGS,
      _Py_isupper__doc__},
     {"join", (PyCFunction)bytearray_join, METH_O, join_doc},
-    {"ljust", (PyCFunction)stringlib_ljust, METH_VARARGS, ljust__doc__},
+    STRINGLIB_LJUST_METHODDEF
     {"lower", (PyCFunction)stringlib_lower, METH_NOARGS, _Py_lower__doc__},
     {"lstrip", (PyCFunction)bytearray_lstrip, METH_VARARGS, lstrip__doc__},
     {"maketrans", (PyCFunction)bytearray_maketrans, METH_VARARGS|METH_STATIC,
@@ -2866,7 +2865,7 @@
     {"reverse", (PyCFunction)bytearray_reverse, METH_NOARGS, reverse__doc__},
     {"rfind", (PyCFunction)bytearray_rfind, METH_VARARGS, rfind__doc__},
     {"rindex", (PyCFunction)bytearray_rindex, METH_VARARGS, rindex__doc__},
-    {"rjust", (PyCFunction)stringlib_rjust, METH_VARARGS, rjust__doc__},
+    STRINGLIB_RJUST_METHODDEF
     {"rpartition", (PyCFunction)bytearray_rpartition, METH_O, rpartition__doc__},
     {"rsplit", (PyCFunction)bytearray_rsplit, METH_VARARGS | METH_KEYWORDS, rsplit__doc__},
     {"rstrip", (PyCFunction)bytearray_rstrip, METH_VARARGS, rstrip__doc__},
@@ -2882,7 +2881,7 @@
     {"translate", (PyCFunction)bytearray_translate, METH_VARARGS,
      translate__doc__},
     {"upper", (PyCFunction)stringlib_upper, METH_NOARGS, _Py_upper__doc__},
-    {"zfill", (PyCFunction)stringlib_zfill, METH_VARARGS, zfill__doc__},
+    STRINGLIB_ZFILL_METHODDEF
     {NULL}
 };
 
diff -r 967f368b7f75 Objects/bytesobject.c
--- a/Objects/bytesobject.c	Sun Jan 19 00:38:36 2014 +0200
+++ b/Objects/bytesobject.c	Tue Jan 21 01:13:17 2014 +0200
@@ -2397,13 +2397,12 @@
     {"__getnewargs__",          (PyCFunction)bytes_getnewargs,  METH_NOARGS},
     {"capitalize", (PyCFunction)stringlib_capitalize, METH_NOARGS,
      _Py_capitalize__doc__},
-    {"center", (PyCFunction)stringlib_center, METH_VARARGS, center__doc__},
+    STRINGLIB_CENTER_METHODDEF
     {"count", (PyCFunction)bytes_count, METH_VARARGS, count__doc__},
     {"decode", (PyCFunction)bytes_decode, METH_VARARGS | METH_KEYWORDS, decode__doc__},
     {"endswith", (PyCFunction)bytes_endswith, METH_VARARGS,
      endswith__doc__},
-    {"expandtabs", (PyCFunction)stringlib_expandtabs, METH_VARARGS | METH_KEYWORDS,
-     expandtabs__doc__},
+    STRINGLIB_EXPANDTABS_METHODDEF
     {"find", (PyCFunction)bytes_find, METH_VARARGS, find__doc__},
     {"fromhex", (PyCFunction)bytes_fromhex, METH_VARARGS|METH_CLASS,
      fromhex_doc},
@@ -2423,7 +2422,7 @@
     {"isupper", (PyCFunction)stringlib_isupper, METH_NOARGS,
      _Py_isupper__doc__},
     {"join", (PyCFunction)bytes_join, METH_O, join__doc__},
-    {"ljust", (PyCFunction)stringlib_ljust, METH_VARARGS, ljust__doc__},
+    STRINGLIB_LJUST_METHODDEF
     {"lower", (PyCFunction)stringlib_lower, METH_NOARGS, _Py_lower__doc__},
     {"lstrip", (PyCFunction)bytes_lstrip, METH_VARARGS, lstrip__doc__},
     {"maketrans", (PyCFunction)bytes_maketrans, METH_VARARGS|METH_STATIC,
@@ -2432,7 +2431,7 @@
     {"replace", (PyCFunction)bytes_replace, METH_VARARGS, replace__doc__},
     {"rfind", (PyCFunction)bytes_rfind, METH_VARARGS, rfind__doc__},
     {"rindex", (PyCFunction)bytes_rindex, METH_VARARGS, rindex__doc__},
-    {"rjust", (PyCFunction)stringlib_rjust, METH_VARARGS, rjust__doc__},
+    STRINGLIB_RJUST_METHODDEF
     {"rpartition", (PyCFunction)bytes_rpartition, METH_O,
      rpartition__doc__},
     {"rsplit", (PyCFunction)bytes_rsplit, METH_VARARGS | METH_KEYWORDS, rsplit__doc__},
@@ -2449,7 +2448,7 @@
     {"translate", (PyCFunction)bytes_translate, METH_VARARGS,
      translate__doc__},
     {"upper", (PyCFunction)stringlib_upper, METH_NOARGS, _Py_upper__doc__},
-    {"zfill", (PyCFunction)stringlib_zfill, METH_VARARGS, zfill__doc__},
+    STRINGLIB_ZFILL_METHODDEF
     {"__sizeof__", (PyCFunction)bytes_sizeof, METH_NOARGS,
      sizeof__doc__},
     {NULL,     NULL}                         /* sentinel */
diff -r 967f368b7f75 Objects/stringlib/transmogrify.h
--- a/Objects/stringlib/transmogrify.h	Sun Jan 19 00:38:36 2014 +0200
+++ b/Objects/stringlib/transmogrify.h	Tue Jan 21 01:13:17 2014 +0200
@@ -4,25 +4,58 @@
 /* the more complicated methods.  parts of these should be pulled out into the
    shared code in bytes_methods.c to cut down on duplicate code bloat.  */
 
-PyDoc_STRVAR(expandtabs__doc__,
-"B.expandtabs(tabsize=8) -> copy of B\n\
-\n\
-Return a copy of B where all tab characters are expanded using spaces.\n\
-If tabsize is not given, a tab size of 8 characters is assumed.");
+/*[clinic input]
+class B
+[clinic start generated code]*/
+/*[clinic end generated code: checksum=da39a3ee5e6b4b0d3255bfef95601890afd80709]*/
 
-static PyObject*
-stringlib_expandtabs(PyObject *self, PyObject *args, PyObject *kwds)
+/*[clinic input]
+B.expandtabs as stringlib_expandtabs
+
+    tabsize: int = 8
+
+Return a copy where all tab characters are expanded using spaces.
+
+If tabsize is not given, a tab size of 8 characters is assumed.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(stringlib_expandtabs__doc__,
+"expandtabs(tabsize=8)\n"
+"Return a copy where all tab characters are expanded using spaces.\n"
+"\n"
+"If tabsize is not given, a tab size of 8 characters is assumed.");
+
+#define STRINGLIB_EXPANDTABS_METHODDEF    \
+    {"expandtabs", (PyCFunction)stringlib_expandtabs, METH_VARARGS|METH_KEYWORDS, stringlib_expandtabs__doc__},
+
+static PyObject *
+stringlib_expandtabs_impl(PyObject *self, int tabsize);
+
+static PyObject *
+stringlib_expandtabs(PyObject *self, PyObject *args, PyObject *kwargs)
+{
+    PyObject *return_value = NULL;
+    static char *_keywords[] = {"tabsize", NULL};
+    int tabsize = 8;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs,
+        "|i:expandtabs", _keywords,
+        &tabsize))
+        goto exit;
+    return_value = stringlib_expandtabs_impl(self, tabsize);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+stringlib_expandtabs_impl(PyObject *self, int tabsize)
+/*[clinic end generated code: checksum=3d651d40c2ceac014766ddbb1fdbaf5266672bbb]*/
 {
     const char *e, *p;
     char *q;
     size_t i, j;
     PyObject *u;
-    static char *kwlist[] = {"tabsize", 0};
-    int tabsize = 8;
-
-    if (!PyArg_ParseTupleAndKeywords(args, kwds, "|i:expandtabs",
-                                     kwlist, &tabsize))
-        return NULL;
 
     /* First pass: determine size of output string */
     i = j = 0;
@@ -120,21 +153,51 @@
     return u;
 }
 
-PyDoc_STRVAR(ljust__doc__,
-"B.ljust(width[, fillchar]) -> copy of B\n"
+/*[clinic input]
+B.ljust as stringlib_ljust
+
+    width: Py_ssize_t
+    fillchar: char(c_default="' '", py_default="b' '") = ' '
+    /
+
+Return a left-justified string of length width.
+
+Padding is done using the specified fill character (default is a space).
+[clinic start generated code]*/
+
+PyDoc_STRVAR(stringlib_ljust__doc__,
+"ljust(width, fillchar=b\' \')\n"
+"Return a left-justified string of length width.\n"
 "\n"
-"Return B left justified in a string of length width. Padding is\n"
-"done using the specified fill character (default is a space).");
+"Padding is done using the specified fill character (default is a space).");
+
+#define STRINGLIB_LJUST_METHODDEF    \
+    {"ljust", (PyCFunction)stringlib_ljust, METH_VARARGS, stringlib_ljust__doc__},
+
+static PyObject *
+stringlib_ljust_impl(PyObject *self, Py_ssize_t width, char fillchar);
 
 static PyObject *
 stringlib_ljust(PyObject *self, PyObject *args)
 {
+    PyObject *return_value = NULL;
     Py_ssize_t width;
     char fillchar = ' ';
 
-    if (!PyArg_ParseTuple(args, "n|c:ljust", &width, &fillchar))
-        return NULL;
+    if (!PyArg_ParseTuple(args,
+        "n|c:ljust",
+        &width, &fillchar))
+        goto exit;
+    return_value = stringlib_ljust_impl(self, width, fillchar);
 
+exit:
+    return return_value;
+}
+
+static PyObject *
+stringlib_ljust_impl(PyObject *self, Py_ssize_t width, char fillchar)
+/*[clinic end generated code: checksum=b0c5f9af52331f2c7278a4dbc8dfa16c664e98e8]*/
+{
     if (STRINGLIB_LEN(self) >= width && STRINGLIB_CHECK_EXACT(self)) {
 #if STRINGLIB_MUTABLE
         /* We're defined as returning a copy;  If the object is mutable
@@ -149,22 +212,51 @@
     return pad(self, 0, width - STRINGLIB_LEN(self), fillchar);
 }
 
+/*[clinic input]
+B.rjust as stringlib_rjust
 
-PyDoc_STRVAR(rjust__doc__,
-"B.rjust(width[, fillchar]) -> copy of B\n"
+    width: Py_ssize_t
+    fillchar: char(c_default="' '", py_default="b' '") = ' '
+    /
+
+Return a right-justified string of length width.
+
+Padding is done using the specified fill character (default is a space).
+[clinic start generated code]*/
+
+PyDoc_STRVAR(stringlib_rjust__doc__,
+"rjust(width, fillchar=b\' \')\n"
+"Return a right-justified string of length width.\n"
 "\n"
-"Return B right justified in a string of length width. Padding is\n"
-"done using the specified fill character (default is a space)");
+"Padding is done using the specified fill character (default is a space).");
+
+#define STRINGLIB_RJUST_METHODDEF    \
+    {"rjust", (PyCFunction)stringlib_rjust, METH_VARARGS, stringlib_rjust__doc__},
+
+static PyObject *
+stringlib_rjust_impl(PyObject *self, Py_ssize_t width, char fillchar);
 
 static PyObject *
 stringlib_rjust(PyObject *self, PyObject *args)
 {
+    PyObject *return_value = NULL;
     Py_ssize_t width;
     char fillchar = ' ';
 
-    if (!PyArg_ParseTuple(args, "n|c:rjust", &width, &fillchar))
-        return NULL;
+    if (!PyArg_ParseTuple(args,
+        "n|c:rjust",
+        &width, &fillchar))
+        goto exit;
+    return_value = stringlib_rjust_impl(self, width, fillchar);
 
+exit:
+    return return_value;
+}
+
+static PyObject *
+stringlib_rjust_impl(PyObject *self, Py_ssize_t width, char fillchar)
+/*[clinic end generated code: checksum=18ff32c71a37a5bdb1eddac584ff864ad4e1be17]*/
+{
     if (STRINGLIB_LEN(self) >= width && STRINGLIB_CHECK_EXACT(self)) {
 #if STRINGLIB_MUTABLE
         /* We're defined as returning a copy;  If the object is mutable
@@ -179,22 +271,52 @@
     return pad(self, width - STRINGLIB_LEN(self), 0, fillchar);
 }
 
+/*[clinic input]
+B.center as stringlib_center
 
-PyDoc_STRVAR(center__doc__,
-"B.center(width[, fillchar]) -> copy of B\n"
+    width: Py_ssize_t
+    fillchar: char(c_default="' '", py_default="b' '") = ' '
+    /
+
+Return a centered string of length width.
+
+Padding is done using the specified fill character (default is a space).
+[clinic start generated code]*/
+
+PyDoc_STRVAR(stringlib_center__doc__,
+"center(width, fillchar=b\' \')\n"
+"Return a centered string of length width.\n"
 "\n"
-"Return B centered in a string of length width.  Padding is\n"
-"done using the specified fill character (default is a space).");
+"Padding is done using the specified fill character (default is a space).");
+
+#define STRINGLIB_CENTER_METHODDEF    \
+    {"center", (PyCFunction)stringlib_center, METH_VARARGS, stringlib_center__doc__},
+
+static PyObject *
+stringlib_center_impl(PyObject *self, Py_ssize_t width, char fillchar);
 
 static PyObject *
 stringlib_center(PyObject *self, PyObject *args)
 {
-    Py_ssize_t marg, left;
+    PyObject *return_value = NULL;
     Py_ssize_t width;
     char fillchar = ' ';
 
-    if (!PyArg_ParseTuple(args, "n|c:center", &width, &fillchar))
-        return NULL;
+    if (!PyArg_ParseTuple(args,
+        "n|c:center",
+        &width, &fillchar))
+        goto exit;
+    return_value = stringlib_center_impl(self, width, fillchar);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+stringlib_center_impl(PyObject *self, Py_ssize_t width, char fillchar)
+/*[clinic end generated code: checksum=681c08ac05f140085f0fbbe08289444629de158f]*/
+{
+    Py_ssize_t marg, left;
 
     if (STRINGLIB_LEN(self) >= width && STRINGLIB_CHECK_EXACT(self)) {
 #if STRINGLIB_MUTABLE
@@ -213,22 +335,52 @@
     return pad(self, left, marg - left, fillchar);
 }
 
-PyDoc_STRVAR(zfill__doc__,
-"B.zfill(width) -> copy of B\n"
+/*[clinic input]
+B.zfill as stringlib_zfill
+
+    width: Py_ssize_t
+    /
+
+Pad a numeric string with zeros on the left, to fill a field of the given width.
+
+The original string is never truncated.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(stringlib_zfill__doc__,
+"zfill(width)\n"
+"Pad a numeric string with zeros on the left, to fill a field of the given width.\n"
 "\n"
-"Pad a numeric string B with zeros on the left, to fill a field\n"
-"of the specified width.  B is never truncated.");
+"The original string is never truncated.");
+
+#define STRINGLIB_ZFILL_METHODDEF    \
+    {"zfill", (PyCFunction)stringlib_zfill, METH_VARARGS, stringlib_zfill__doc__},
+
+static PyObject *
+stringlib_zfill_impl(PyObject *self, Py_ssize_t width);
 
 static PyObject *
 stringlib_zfill(PyObject *self, PyObject *args)
 {
+    PyObject *return_value = NULL;
+    Py_ssize_t width;
+
+    if (!PyArg_ParseTuple(args,
+        "n:zfill",
+        &width))
+        goto exit;
+    return_value = stringlib_zfill_impl(self, width);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+stringlib_zfill_impl(PyObject *self, Py_ssize_t width)
+/*[clinic end generated code: checksum=ab4b4f727ae444586aa3ecbcf3d3be16c4e70863]*/
+{
     Py_ssize_t fill;
     PyObject *s;
     char *p;
-    Py_ssize_t width;
-
-    if (!PyArg_ParseTuple(args, "n:zfill", &width))
-        return NULL;
 
     if (STRINGLIB_LEN(self) >= width) {
         if (STRINGLIB_CHECK_EXACT(self)) {