How do I cause or create an invalid memory reference in Python on purpose?

Question

How do I cause or create an invalid memory reference in Python on purpose?

This is a bit of a bar-bet. I'm told it can't be done. I don't believe that.

Answer 1

>>> import ctypes
>>> p = ctypes.POINTER(ctypes.c_int)(ctypes.c_int())
>>> p[100000000]
Segmentation fault

Answer 2

Create a module in C:

#include <Python.h>

static PyMethodDef SpamMethods[] =
{
    {NULL, NULL, 0, NULL}
};

PyMODINIT_FUNC
initspam(void)
{
    (void)Py_InitModule("spam", SpamMethods);
    int* invalidptr = NULL;
    *invalidptr = 42;
}

And then from python:

import spam