PyObject* aa = PyLong_FromLong(7L);

PyObject* aa = PyLong_FromLong(257L);

PyObject* PyLong_FromLong(long v)
Return value: New reference.
Return a new PyLongObject object from v, or NULL on failure.

The current implementation keeps an array of integer objects for all integers between -5 and 256, when you create an int in that range you actually just get back a reference to the existing object. So it should be possible to change the value of 1. I suspect the behaviour of Python in this case is undefined. :-)