Make typing_extensions optional again

optuna_dashboard/_app.py

@@ -29,7 +29,6 @@ from optuna.version import __version__ as optuna_ver
 from packaging import version
 
 from . import _note as note
-from . import artifact
 from ._bottle_util import BottleViewReturn
 from ._bottle_util import json_api_view
 from ._cached_extra_study_property import get_cached_extra_study_property
@@ -43,6 +42,7 @@ from .artifact._backend import register_artifact_route
 
 if typing.TYPE_CHECKING:
     from _typeshed.wsgi import WSGIApplication
+    from optuna_dashboard.artifact.protocol import ArtifactBackend
 
     try:
         from optuna.study._frozen import FrozenStudy
@@ -182,7 +182,7 @@ def get_trials(storage: BaseStorage, study_id: int, ttl_seconds: int = 10) -> li
 
 def create_app(
     storage: BaseStorage,
-    artifact_backend: Optional[artifact.ArtifactBackend] = None,
+    artifact_backend: Optional[ArtifactBackend] = None,
     debug: bool = False,
 ) -> Bottle:
     app = Bottle()

optuna_dashboard/artifact/__init__.py

@@ -1,2 +1 @@
-from ._backend import ArtifactBackend  # noqa
 from ._backend import upload_artifact  # noqa

optuna_dashboard/artifact/_backend.py

@@ -15,20 +15,15 @@ from .._bottle_util import json_api_view
 from .._bottle_util import parse_data_uri
 
 
-try:
-    from typing import Protocol
-except ImportError:
-    from typing_extensions import Protocol  # type: ignore
-
-
 if TYPE_CHECKING:
     from typing import Any
-    from typing import BinaryIO
     from typing import Optional
     from typing import TypedDict
 
     from optuna.storages import BaseStorage
 
+    from .protocol import ArtifactBackend
+
     ArtifactMeta = TypedDict(
         "ArtifactMeta",
         {
@@ -44,17 +39,6 @@ ARTIFACTS_ATTR_PREFIX = "dashboard:artifacts:"
 DEFAULT_MIME_TYPE = "application/octet-stream"
 
 
-class ArtifactBackend(Protocol):
-    def open(self, artifact_id: str) -> BinaryIO:
-        ...
-
-    def write(self, artifact_id: str, content_body: BinaryIO) -> None:
-        ...
-
-    def remove(self, artifact_id: str) -> None:
-        ...
-
-
 def register_artifact_route(
     app: Bottle, storage: BaseStorage, artifact_backend: Optional[ArtifactBackend]
 ) -> None:

optuna_dashboard/artifact/boto3.py

@@ -51,6 +51,6 @@ class Boto3Backend:
 if TYPE_CHECKING:
     # A mypy-runtime assertion to ensure that Boto3Backend
     # implements all abstract methods in ArtifactBackendProtocol.
-    from ._backend import ArtifactBackend
+    from .protocol import ArtifactBackend
 
     _: ArtifactBackend = Boto3Backend("")

optuna_dashboard/artifact/file_system.py

@@ -26,6 +26,6 @@ class FileSystemBackend:
 if TYPE_CHECKING:
     # A mypy-runtime assertion to ensure that LocalArtifactBackend
     # implements all abstract methods in ArtifactBackendProtocol.
-    from ._backend import ArtifactBackend
+    from .protocol import ArtifactBackend
 
     _: ArtifactBackend = FileSystemBackend("")

optuna_dashboard/artifact/protocol.py

@@ -0,0 +1,13 @@
+from typing import BinaryIO
+from typing import Protocol
+
+
+class ArtifactBackend(Protocol):
+    def open(self, artifact_id: str) -> BinaryIO:
+        ...
+
+    def write(self, artifact_id: str, content_body: BinaryIO) -> None:
+        ...
+
+    def remove(self, artifact_id: str) -> None:
+        ...

pyproject.toml

@@ -30,7 +30,6 @@ dependencies = [
     "optuna>=2.4.0",
     "packaging",
     "scikit-learn",
-    'typing-extensions; python_version<"3.8"',
 ]
 dynamic = ["version"]