split python and arrow

src/data_holder/arrow_helpers.rs

@@ -1,27 +1,6 @@
 //! helpers for arrow
-use std::sync::Arc;
-
-use arrow::array::{
-    make_array, Array, ArrayData, BinaryArray, LargeBinaryArray, LargeStringArray, StringArray,
-};
+use arrow::array::{Array, BinaryArray, LargeBinaryArray, LargeStringArray, StringArray};
 use arrow::datatypes::DataType;
-use arrow::pyarrow::PyArrowType;
-use pyo3::prelude::*;
-use pyo3::PyResult;
-
-/// Take an arrow array from python and convert it to a rust arrow array.
-/// This operation does not copy data.
-#[allow(dead_code)]
-pub fn array_to_rust(arrow_array: PyArrowType<ArrayData>) -> PyResult<Arc<dyn Array>> {
-    // prepare a pointer to receive the Array struct
-    let array = arrow_array.0; // Extract from PyArrowType wrapper
-    Ok(make_array(array))
-}
-
-/// Arrow array to Python.
-pub(crate) fn to_py_array(_: Python, array: Arc<dyn Array>) -> PyResult<PyArrowType<ArrayData>> {
-    Ok(PyArrowType(array.into_data()))
-}
 
 /// returns the number of bits corresponding to the array's datatype
 pub fn arrow_bit_count(array: &dyn Array) -> u32 {

src/export/mod.rs

@@ -1,5 +1,6 @@
 //! Module to export mdf files to other file formats.
 pub mod numpy;
+pub mod python_arrow_helpers;
 //pub mod parquet;
 pub mod polars;
 // pub mod tensor;

src/export/polars.rs

@@ -4,7 +4,7 @@ use std::sync::Arc;
 use arrow::array::Array;
 use pyo3::{types::PyList, PyObject, PyResult, ToPyObject};
 
-use crate::data_holder::arrow_helpers::to_py_array;
+use crate::export::python_arrow_helpers::to_py_array;
 
 /// converts rust arrow array into python polars series
 #[allow(dead_code)]

src/export/python_arrow_helpers.rs

@@ -0,0 +1,21 @@
+//! helpers for arrow use with python
+use std::sync::Arc;
+
+use arrow::array::{make_array, Array, ArrayData};
+use arrow::pyarrow::PyArrowType;
+use pyo3::prelude::*;
+use pyo3::PyResult;
+
+/// Take an arrow array from python and convert it to a rust arrow array.
+/// This operation does not copy data.
+#[allow(dead_code)]
+pub fn array_to_rust(arrow_array: PyArrowType<ArrayData>) -> PyResult<Arc<dyn Array>> {
+    // prepare a pointer to receive the Array struct
+    let array = arrow_array.0; // Extract from PyArrowType wrapper
+    Ok(make_array(array))
+}
+
+/// Arrow array to Python.
+pub(crate) fn to_py_array(_: Python, array: Arc<dyn Array>) -> PyResult<PyArrowType<ArrayData>> {
+    Ok(PyArrowType(array.into_data()))
+}

src/mdfr.rs

@@ -2,8 +2,8 @@
 use std::collections::HashSet;
 use std::fmt::Write;
 
-use crate::data_holder::arrow_helpers::array_to_rust;
 use crate::export::polars::rust_arrow_to_py_series;
+use crate::export::python_arrow_helpers::array_to_rust;
 use crate::mdfinfo::MdfInfo;
 use crate::mdfreader::MasterSignature;
 use crate::mdfreader::Mdf;