python_to_rust.rs

fn vec_to_numpy<>(py: Python, vec: Vec<ResultData>) -> PyResult<PyObject> {
    let numpy: &PyAny = PyModule::import(py, "numpy")?;
    let dtype: Py<PyList> = PyList::new(py, &vec![
        ("day", "datetime64[D]"),
        ("h3_index", "S15"), ("sunrise", "datetime64[s]"),
        ("sunset", "datetime64[s]"),
        ("midnight", "datetime64[s]")]).into_py(py);

    let length_py: Py<PyLong> = to_py_int(py, vec.len() as c_long)?;
    let length_any_py: Py<PyAny> = length_py.into_any();
    let length: &PyAny = length_any_py.as_ref(py);
    let dtype_as_py: &PyAny = dtype.as_ref(py);
    let locals: Bound<PyDict> = [("np", numpy), ("size", length), ("dtype", dtype_as_py)].into_py_dict_bound(py);

    const CODE: &str = r#"
empty_array = np.empty(size, dtype=dtype)"#;

    py.run_bound(CODE, None, Some(&locals)).expect("It did not work");

    let np_array = locals.as_ref().get_item("empty_array")?;

    for (i, ResultData { duration_days: duration_days, h3_index: h3_index, sunrise: sunrise, sunset: sunset, midnight: midnight }) in vec.iter().enumerate() {
        let duration_days_py: &Py<PyAny> = &to_py_int(py, duration_days.clone() / (24*3600))?.into_any();
        let h3_index_py: &Py<PyAny> = &PyBytes::new_bound(py, h3_index).unbind().into_any();
        let sunrise_py: &Py<PyAny> = &to_py_int(py, sunrise.clone())?.into_any();
        let sunset_py: &Py<PyAny> = &to_py_int(py, sunset.clone())?.into_any();
        let midnight_py: &Py<PyAny> = &to_py_int(py, midnight.clone())?.into_any();

        let elements: Bound<PyTuple> = PyTuple::new_bound(py, [duration_days_py, h3_index_py, sunrise_py, sunset_py, midnight_py]);

        let value = PyTuple::new_bound(py, elements);
        let as_py_int = to_py_int(py, i as c_long)?.clone();

        np_array.call_method1("__setitem__", (as_py_int, value))?;
    }

    Ok(np_array.into())
}