Support numpy scalars in Trial.user_attrs

python_tests/test_serializers.py

@@ -2,6 +2,7 @@ from __future__ import annotations
 
 import sys
 
+import numpy as np
 import optuna
 from optuna_dashboard._serializer import serialize_attrs
 from optuna_dashboard._serializer import serialize_study_detail
@@ -25,6 +26,32 @@ def test_serialize_dict() -> None:
     assert len(serialized) <= 1
 
 
+def test_serialize_numpy_integer() -> None:
+    serialized = serialize_attrs(
+        {
+            "int8": np.int8(1),
+            "int16": np.int16(1),
+            "int32": np.int32(1),
+            "int64": np.int64(1),
+        }
+    )
+    assert len(serialized) == 4
+    assert all([v["value"] == 1 for v in serialized])
+
+
+def test_serialize_numpy_floating() -> None:
+    serialized = serialize_attrs(
+        {
+            "float16": np.float16(1.0),
+            "float32": np.float32(1.0),
+            "float64": np.float64(1.0),
+            "float128": np.float128(1.0),
+        }
+    )
+    assert len(serialized) == 4
+    assert all([v["value"] == 1.0 for v in serialized])
+
+
 @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
 def test_get_study_detail_is_preferential() -> None:
     storage = optuna.storages.InMemoryStorage()