Why doesn't PyRun_String evaluate bool literals

PyObject * dict = PyDict_New();
PyObject * val = PyRun_String(expression, Py_eval_input, dict, 0);
Py_DECREF(dict);

PyObject* PyRun_String(const char *str, int start, PyObject *globals, PyObject *locals);

if (PyDict_GetItemString(globals, "__builtins__") == NULL) {
    if (PyDict_SetItemString(globals, "__builtins__",
                 PyEval_GetBuiltins()) != 0)
        return NULL;
}