I would have expected a bool parse code to insist on a boolean, so that:

    int x;
    PyArg_ParseTupleAndKeywords(args, kwds, "p:func", &x);

would behave the same as:

    PyObject  *o;
    int x;
    PyArg_ParseTupleAndKeywords(args, kwds, "O!:func", &PyBool_Type, &o);
    x = o == Py_True;