Index: Objects/unicodeobject.c
===================================================================
--- Objects/unicodeobject.c	(revision 43573)
+++ Objects/unicodeobject.c	(working copy)
@@ -5282,7 +5282,30 @@
     return result;
 }
 
+PyDoc_STRVAR(format__doc__,
+"S.format(ARGS | KWARGS) -> str\n\
+\n\
+format the string.");
+
 static PyObject *
+unicode_format(PyUnicodeObject *self, PyObject *args, PyObject *kwds)
+{
+	int a, k;
+	a = PyObject_Length(args);
+	k = PyObject_Length(kwds);
+	if ((a > 0) && (k > 0)) {
+		PyErr_SetString \
+		  (PyExc_ValueError,
+		   "format requires positional or keyword args, not both");
+		return NULL;
+	} else if (k > 0) {
+		return PyUnicode_Format(self, kwds);
+	} else {
+		return PyUnicode_Format(self, args);
+	}
+}
+
+static PyObject *
 unicode_getitem(PyUnicodeObject *self, Py_ssize_t index)
 {
     if (index < 0 || index >= self->length) {
@@ -6391,6 +6414,8 @@
     {"count", (PyCFunction) unicode_count, METH_VARARGS, count__doc__},
     {"expandtabs", (PyCFunction) unicode_expandtabs, METH_VARARGS, expandtabs__doc__},
     {"find", (PyCFunction) unicode_find, METH_VARARGS, find__doc__},
+    {"format", (PyCFunction) unicode_format, METH_VARARGS | METH_KEYWORDS,
+     format__doc__},
     {"index", (PyCFunction) unicode_index, METH_VARARGS, index__doc__},
     {"ljust", (PyCFunction) unicode_ljust, METH_VARARGS, ljust__doc__},
     {"lower", (PyCFunction) unicode_lower, METH_NOARGS, lower__doc__},
Index: Objects/stringobject.c
===================================================================
--- Objects/stringobject.c	(revision 43573)
+++ Objects/stringobject.c	(working copy)
@@ -1806,7 +1806,29 @@
 	return PyInt_FromSsize_t(result);
 }
 
+PyDoc_STRVAR(format__doc__,
+"S.format(ARGS | KWARGS) -> str\n\
+\n\
+format the string.");
 
+static PyObject *
+string_format(PyStringObject *self, PyObject *args, PyObject *kwds)
+{
+	int a, k;
+	a = PyObject_Length(args);
+	k = PyObject_Length(kwds);
+	if ((a > 0) && (k > 0)) {
+		PyErr_SetString \
+		  (PyExc_ValueError,
+		   "format requires positional or keyword args, not both");
+		return NULL;
+	} else if (k > 0) {
+		return PyString_Format(self, kwds);
+	} else {
+		return PyString_Format(self, args);
+	}
+}
+
 PyDoc_STRVAR(index__doc__,
 "S.index(sub [,start [,end]]) -> int\n\
 \n\
@@ -3306,6 +3328,8 @@
 	{"endswith", (PyCFunction)string_endswith, METH_VARARGS,
 	 endswith__doc__},
 	{"find", (PyCFunction)string_find, METH_VARARGS, find__doc__},
+	{"format", (PyCFunction)string_format, METH_VARARGS | METH_KEYWORDS,
+	 format__doc__},
 	{"index", (PyCFunction)string_index, METH_VARARGS, index__doc__},
 	{"lstrip", (PyCFunction)string_lstrip, METH_VARARGS, lstrip__doc__},
 	{"replace", (PyCFunction)string_replace, METH_VARARGS, replace__doc__},