Use flake8

optuna_dashboard/app.py

@@ -95,9 +95,9 @@ def create_app(storage_or_url: Union[str, BaseStorage]) -> Bottle:
     app = Bottle()
     storage = get_storage(storage_or_url)
 
-    @hook('before_request')
+    @hook("before_request")
     def remove_trailing_slashes_hook():
-        request.environ['PATH_INFO'] = request.environ['PATH_INFO'].rstrip('/')
+        request.environ["PATH_INFO"] = request.environ["PATH_INFO"].rstrip("/")
 
     @app.get("/")
     def index():

setup.cfg

@@ -0,0 +1,4 @@
+[flake8]
+max-line-length = 99
+statistics = True
+exclude = venv,build

setup.py

@@ -34,11 +34,11 @@ setup(
     packages=find_packages(),
     install_requires=["optuna", "bottle"],
     extras_require={
-        "lint": ["black"],
+        "lint": ["black", "flake8"],
         "release": ["wheel", "twine"],
     },
     package_data={"optuna_dashboard": ["public/*"]},
-    test_suite='tests',
+    test_suite="tests",
     entry_points={
         "console_scripts": [
             "optuna-dashboard = optuna_dashboard.cli:main",