feat: change into_view method to public and update test for async SQL execution

Author: kosiew

src/dataframe.rs

@@ -405,7 +405,7 @@ impl PyDataFrame {
     /// https://github.com/apache/datafusion-python/pull/1016#discussion_r1983239116
     /// - we have not decided on the table_provider approach yet
     #[allow(clippy::wrong_self_convention)]
-    fn into_view(&self) -> PyDataFusionResult<PyTableProvider> {
+    pub fn into_view(&self) -> PyDataFusionResult<PyTableProvider> {
         // Call the underlying Rust DataFrame::into_view method.
         // Note that the Rust method consumes self; here we clone the inner Arc<DataFrame>
         // so that we don’t invalidate this PyDataFrame.

tests/dataframe_into_view.rs

@@ -30,9 +30,10 @@ fn dataframe_into_view_returns_table_provider() {
         .unwrap();
 
     let rt = tokio::runtime::Runtime::new().unwrap();
-    let batches = rt
-        .block_on(ctx.sql("SELECT * FROM view").unwrap().collect())
-        .unwrap();
+    let batches = rt.block_on(async {
+        let df = ctx.sql("SELECT * FROM view").await.unwrap();
+        df.collect().await.unwrap()
+    });
 
     assert_eq!(batches.len(), 1);
     assert_eq!(batches[0].num_rows(), 3);