Merge pull request #647 from not522/gpsampler-default

Make `PreferentialGPSampler` the default for preferential optimization

optuna_dashboard/preferential/_study.py

@@ -7,9 +7,9 @@ from typing import Iterable
 
 import optuna
 from optuna import logging
+from optuna._imports import try_import
 from optuna.distributions import BaseDistribution
 from optuna.samplers import BaseSampler
-from optuna.samplers import RandomSampler
 from optuna.trial import FrozenTrial
 from optuna.trial import TrialState
 from optuna_dashboard.preferential._system_attrs import get_n_generate
@@ -20,6 +20,10 @@ from optuna_dashboard.preferential._system_attrs import report_preferences
 from optuna_dashboard.preferential._system_attrs import set_n_generate
 
 
+with try_import() as _imports:
+    from optuna_dashboard.preferential.samplers.gp import PreferentialGPSampler
+
+
 _logger = logging.get_logger(__name__)
 _SYSTEM_ATTR_PREFERENTIAL_STUDY = "preference:is_preferential"
 
@@ -344,11 +348,10 @@ def create_study(
 
         sampler:
             A sampler object that implements background algorithm for value suggestion.
-            If :obj:`None` is specified, `RandomSampler`_ is used. Please note that
-            most Optuna samplers does not work efficiently for preferential optimization.
-
-            .. _RandomSampler: https://optuna.readthedocs.io/en/stable/reference/\
-            samplers/generated/optuna.samplers.RandomSampler.html
+            If :obj:`None` is specified,
+            :class:`~optuna_dashboard.preferential.samplers.gp.PreferentialGPSampler` is used.
+            Please note that most Optuna samplers does not work efficiently for preferential
+            optimization.
 
         study_name:
             Study's name. If this argument is set to None, a unique name is generated
@@ -369,9 +372,13 @@ def create_study(
         The interface may change in newer versions without prior notice.
     """
     try:
+        if sampler is None:
+            _imports.check()  # If BoTorch is not installed, raise ImportError.
+            sampler = PreferentialGPSampler()
+
         study = optuna.create_study(
             storage=storage,
-            sampler=sampler or RandomSampler(),
+            sampler=sampler,
             study_name=study_name,
         )
         study._storage.set_study_system_attr(
@@ -441,11 +448,10 @@ def load_study(
             :func:`~optuna.study.create_study` for further details.
         sampler:
             A sampler object that implements background algorithm for value suggestion.
-            If :obj:`None` is specified, `RandomSampler`_ is used. Please note that
-            most Optuna samplers does not work efficiently for preferential optimization.
-
-            .. _RandomSampler: https://optuna.readthedocs.io/en/stable/reference/samplers/\
-            generated/optuna.samplers.RandomSampler.html
+            If :obj:`None` is specified,
+            :class:`~optuna_dashboard.preferential.samplers.gp.PreferentialGPSampler` is used.
+            Please note that most Optuna samplers does not work efficiently for preferential
+            optimization.
 
     Returns:
         A :class:`~optuna_dashboard.preferential.PreferentialStudy` object.
@@ -454,9 +460,11 @@ def load_study(
         Preferential optimization is an experimental feature (introduced in v0.13.0).
         The interface may change in newer versions without prior notice.
     """
-    study = optuna.load_study(
-        study_name=study_name, storage=storage, sampler=sampler or RandomSampler()
-    )
+    if sampler is None:
+        _imports.check()  # If BoTorch is not installed, raise ImportError.
+        sampler = PreferentialGPSampler()
+
+    study = optuna.load_study(study_name=study_name, storage=storage, sampler=sampler)
     system_attrs = study._storage.get_study_system_attrs(study._study_id)
     if not system_attrs.get(_SYSTEM_ATTR_PREFERENTIAL_STUDY):
         raise ValueError("The study is not a PreferentialStudy.")

python_tests/preferential/test_study.py

@@ -3,6 +3,7 @@ from __future__ import annotations
 import copy
 import multiprocessing
 import pickle
+import sys
 from typing import Callable
 from unittest.mock import patch
 import uuid
@@ -22,6 +23,10 @@ from ..storage_supplier import parametrize_storages
 from ..storage_supplier import StorageSupplier
 
 
+if sys.version_info < (3, 8):
+    pytest.skip("BoTorch dropped Python3.7 support", allow_module_level=True)
+
+
 @parametrize_storages
 def test_study_set_and_get_user_attrs(storage_supplier: Callable[[], StorageSupplier]) -> None:
     with storage_supplier() as storage:

python_tests/test_api.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import sys
 from unittest import TestCase
 
 import optuna
@@ -14,6 +15,7 @@ from optuna_dashboard._preferential_history import remove_history
 from optuna_dashboard._preferential_history import report_history
 from optuna_dashboard._serializer import serialize_preference_history
 from optuna_dashboard.preferential import create_study
+import pytest
 
 from .wsgi_client import send_request
 
@@ -105,6 +107,7 @@ class APITestCase(TestCase):
         )
         self.assertEqual(status, 400)
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_get_best_trials_of_preferential_study(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(n_generate=4, storage=storage)
@@ -128,6 +131,7 @@ class APITestCase(TestCase):
         assert len(best_trials) == 1
         assert best_trials[0]["number"] == 0
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_report_preference(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(n_generate=4, storage=storage)
@@ -161,6 +165,7 @@ class APITestCase(TestCase):
         assert better.number == 2
         assert worse.number == 1
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_report_preference_when_typo_mode(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(storage=storage, n_generate=3)
@@ -184,6 +189,7 @@ class APITestCase(TestCase):
         )
         self.assertEqual(status, 400)
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_change_component(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(storage=storage, n_generate=3)
@@ -214,6 +220,7 @@ class APITestCase(TestCase):
         assert study_detail["feedback_component_type"]["output_type"] == "artifact"
         assert study_detail["feedback_component_type"]["artifact_key"] == "image"
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_skip_trial(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(n_generate=4, storage=storage)
@@ -238,6 +245,7 @@ class APITestCase(TestCase):
         assert len(best_trials) == 1
         assert best_trials[0].number == 2
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_remove_history(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(storage=storage, n_generate=3)
@@ -271,6 +279,7 @@ class APITestCase(TestCase):
         assert histories[0]["is_removed"]
         assert len(study.get_preferences()) == 0
 
+    @pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
     def test_restore_history(self) -> None:
         storage = optuna.storages.InMemoryStorage()
         study = create_study(storage=storage, n_generate=3)

python_tests/test_preferential_history.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import json
+import sys
 from typing import Callable
 from typing import TYPE_CHECKING
 
@@ -13,6 +14,7 @@ from optuna_dashboard._preferential_history import restore_history
 from optuna_dashboard._serializer import serialize_preference_history
 from optuna_dashboard.preferential import create_study
 from optuna_dashboard.preferential._system_attrs import _SYSTEM_ATTR_PREFIX_PREFERENCE
+import pytest
 
 from .storage_supplier import parametrize_storages
 from .storage_supplier import StorageSupplier
@@ -22,6 +24,10 @@ if TYPE_CHECKING:
     from optuna_dashboard._preferential_history import History
 
 
+if sys.version_info < (3, 8):
+    pytest.skip("BoTorch dropped Python3.7 support", allow_module_level=True)
+
+
 @parametrize_storages
 def test_report_and_get_choices(storage_supplier: Callable[[], StorageSupplier]) -> None:
     with storage_supplier() as storage:

python_tests/test_serializers.py

@@ -1,11 +1,14 @@
 from __future__ import annotations
 
+import sys
+
 import optuna
 from optuna_dashboard._serializer import serialize_attrs
 from optuna_dashboard._serializer import serialize_study_detail
 from optuna_dashboard._serializer import serialize_study_summary
 from optuna_dashboard._storage import get_study_summaries
 from optuna_dashboard.preferential import create_study
+import pytest
 
 
 def test_serialize_bytes() -> None:
@@ -22,6 +25,7 @@ def test_serialize_dict() -> None:
     assert len(serialized) <= 1
 
 
+@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()
     study = create_study(n_generate=4, storage=storage)
@@ -48,6 +52,7 @@ def test_get_study_detail_is_not_preferential() -> None:
     assert not study_detail["is_preferential"]
 
 
+@pytest.mark.skipif(sys.version_info < (3, 8), reason="BoTorch dropped Python3.7 support")
 def test_get_study_summary_is_preferential() -> None:
     storage = optuna.storages.InMemoryStorage()
     create_study(n_generate=4, storage=storage)