fix: Add np.ndarray support in nested collection proto conversion and clarify placeholder pyarrow type

soooojinlee · claude · soooojinlee · commit f9ee82db3b2c · 2026-04-02T00:28:51.000+09:00
- Add np.ndarray to isinstance check in _convert_nested_collection_to_proto
  to fix KeyError for 3+ level nesting during materialization (PyArrow produces
  np.ndarray, not Python list)
- Add comment clarifying VALUE_LIST/VALUE_SET placeholder in feast_value_type_to_pa

Co-Authored-By: Claude Opus 4.6 &lt;noreply@anthropic.com&gt;
diff --git a/sdk/python/feast/type_map.py b/sdk/python/feast/type_map.py
@@ -1088,7 +1088,8 @@ def _convert_nested_collection_to_proto(
                         # Empty inner collection: store as empty ProtoValue
                         inner_values.append(ProtoValue())
                     elif any(
-                        isinstance(item, (list, set, tuple)) for item in inner_list
+                        isinstance(item, (list, set, tuple, np.ndarray))
+                        for item in inner_list
                     ):
                         # Deeper nesting (3+ levels): recurse using VALUE_LIST
                         inner_proto = _convert_nested_collection_to_proto(
@@ -1765,6 +1766,8 @@ def feast_value_type_to_pa(
         ValueType.JSON_LIST: pyarrow.list_(pyarrow.large_string()),
         ValueType.STRUCT: pyarrow.struct([]),
         ValueType.STRUCT_LIST: pyarrow.list_(pyarrow.struct([])),
+        # Placeholder: inner type is unknown from ValueType alone.
+        # Callers needing accurate inner types should use from_feast_to_pyarrow_type() with a FeastType.
         ValueType.VALUE_LIST: pyarrow.list_(pyarrow.list_(pyarrow.string())),
         ValueType.VALUE_SET: pyarrow.list_(pyarrow.list_(pyarrow.string())),
         ValueType.NULL: pyarrow.null(),
