Another dummy type.

Curious: Str didn't need me to put something in tp_new, but Null did.
Why the difference?

Modules/xxmodule.c

@@ -260,6 +260,62 @@ static PyTypeObject Str_Type = {
 	0,			/*tp_is_gc*/
 };
 
+/* ---------- */
+
+static PyObject *
+null_richcompare(PyObject *self, PyObject *other, int op)
+{
+	Py_INCREF(Py_NotImplemented);
+	return Py_NotImplemented;
+}
+
+static PyTypeObject Null_Type = {
+	/* The ob_type field must be initialized in the module init function
+	 * to be portable to Windows without using C++. */
+	PyObject_HEAD_INIT(NULL)
+	0,			/*ob_size*/
+	"xxmodule.Null",	/*tp_name*/
+	0,			/*tp_basicsize*/
+	0,			/*tp_itemsize*/
+	/* methods */
+	0,			/*tp_dealloc*/
+	0,			/*tp_print*/
+	0,			/*tp_getattr*/
+	0,			/*tp_setattr*/
+	0,			/*tp_compare*/
+	0,			/*tp_repr*/
+	0,			/*tp_as_number*/
+	0,			/*tp_as_sequence*/
+	0,			/*tp_as_mapping*/
+	0,			/*tp_hash*/
+	0,			/*tp_call*/
+	0,			/*tp_str*/
+	0,			/*tp_getattro*/
+	0,			/*tp_setattro*/
+	0,			/*tp_as_buffer*/
+	Py_TPFLAGS_DEFAULT | Py_TPFLAGS_BASETYPE, /*tp_flags*/
+	0,			/*tp_doc*/
+	0,			/*tp_traverse*/
+	0,			/*tp_clear*/
+	null_richcompare,	/*tp_richcompare*/
+	0,			/*tp_weaklistoffset*/
+	0,			/*tp_iter*/
+	0,			/*tp_iternext*/
+	0,			/*tp_methods*/
+	0,			/*tp_members*/
+	0,			/*tp_getset*/
+	&PyBaseObject_Type,	/*tp_base*/
+	0,			/*tp_dict*/
+	0,			/*tp_descr_get*/
+	0,			/*tp_descr_set*/
+	0,			/*tp_dictoffset*/
+	0,			/*tp_init*/
+	0,			/*tp_alloc*/
+	PyType_GenericNew,	/*tp_new*/
+	0,			/*tp_free*/
+	0,			/*tp_is_gc*/
+};
+
 
 /* ---------- */
 
@@ -310,4 +366,9 @@ initxx(void)
 	if (PyType_Ready(&Str_Type) < 0)
 		return;
 	PyModule_AddObject(m, "Str", (PyObject *)&Str_Type);
+
+	/* Add Null */
+	if (PyType_Ready(&Null_Type) < 0)
+		return;
+	PyModule_AddObject(m, "Null", (PyObject *)&Null_Type);
 }