Fixed Object type for Series

Author: ankane

CHANGELOG.md

@@ -2,6 +2,7 @@
 
 - Added experimental support for Iceberg
 - Added experimental `cast_options` option to `scan_parquet` method
+- Fixed `Object` type for `Series`
 
 ## 0.21.1 (2025-08-18)
 

ext/polars/src/series/mod.rs

@@ -8,13 +8,14 @@ mod import;
 mod map;
 mod scatter;
 
-use magnus::{RArray, Ruby, prelude::*};
+use magnus::{DataTypeFunctions, RArray, Ruby, TypedData, gc, prelude::*};
 use polars::prelude::*;
 use std::cell::RefCell;
 
-use crate::RbResult;
+use crate::{ObjectValue, RbResult};
 
-#[magnus::wrap(class = "Polars::RbSeries")]
+#[derive(TypedData)]
+#[magnus(class = "Polars::RbSeries", mark)]
 pub struct RbSeries {
     pub series: RefCell<Series>,
 }
@@ -48,3 +49,17 @@ pub fn to_rbseries(s: Vec<Column>) -> RArray {
             .map(RbSeries::new),
     )
 }
+
+impl DataTypeFunctions for RbSeries {
+    fn mark(&self, marker: &gc::Marker) {
+        let series = self.series.borrow();
+        if let DataType::Object(_) = series.dtype() {
+            for i in 0..series.len() {
+                let obj: Option<&ObjectValue> = series.get_object(i).map(|any| any.into());
+                if let Some(o) = obj {
+                    marker.mark(o.inner);
+                }
+            }
+        }
+    }
+}

test/types_test.rb

@@ -188,8 +188,7 @@ def test_series_dtype_unknown_utf8
   def test_object
     s = Polars::Series.new([Object.new])
     GC.start
-    # TODO fix
-    # assert s.inspect
+    assert s.inspect
     assert s.to_a
 
     df = Polars::DataFrame.new({a: [Object.new]})