Function retrieve_python_option 

pub fn retrieve_python_option<'py, F>(
    py: Python<'py>,
    buf: &mut [u8],
    offset: usize,
    serde_option: &mut Option<&mut Box<dyn PyAnySerde>>,
    err: F,
) -> PyResult<(Option<Bound<'py, PyAny>>, usize)>
where
    F: FnOnce() -> PyErr,