feat: add columns using pyarrow schema (#2284)

python/src/table.rs

@@ -1,9 +1,11 @@
 // SPDX-License-Identifier: Apache-2.0
 // SPDX-FileCopyrightText: Copyright The LanceDB Authors
+use std::{collections::HashMap, sync::Arc};
+
 use arrow::{
-    datatypes::DataType,
+    datatypes::{DataType, Schema},
     ffi_stream::ArrowArrayStreamReader,
-    pyarrow::{FromPyArrow, ToPyArrow},
+    pyarrow::{FromPyArrow, PyArrowType, ToPyArrow},
 };
 use lancedb::table::{
     AddDataMode, ColumnAlteration, Duration, NewColumnTransform, OptimizeAction, OptimizeOptions,
@@ -16,7 +18,6 @@ use pyo3::{
     Bound, FromPyObject, PyAny, PyRef, PyResult, Python,
 };
 use pyo3_async_runtimes::tokio::future_into_py;
-use std::collections::HashMap;
 
 use crate::{
     error::PythonErrorExt,
@@ -444,6 +445,20 @@ impl Table {
         })
     }
 
+    pub fn add_columns_with_schema(
+        self_: PyRef<'_, Self>,
+        schema: PyArrowType<Schema>,
+    ) -> PyResult<Bound<'_, PyAny>> {
+        let arrow_schema = &schema.0;
+        let transform = NewColumnTransform::AllNulls(Arc::new(arrow_schema.clone()));
+
+        let inner = self_.inner_ref()?.clone();
+        future_into_py(self_.py(), async move {
+            inner.add_columns(transform, None).await.infer_error()?;
+            Ok(())
+        })
+    }
+
     pub fn alter_columns<'a>(
         self_: PyRef<'a, Self>,
         alterations: Vec<Bound<PyDict>>,