Merge pull request #5415 from eukaryo/v4pr-drop-create-study-in-ask

Drop implicit create-study in `ask` command

optuna/cli.py

@@ -727,7 +727,10 @@ def take_action(self, parsed_args: Namespace) -> int:
  )
 
  except KeyError:
- study = optuna.create_study(**create_study_kwargs)
+ raise KeyError(
+ "Implicit study creation within the 'ask' command was dropped in Optuna v4.0.0. "
+ "Please use the 'create-study' command beforehand."
+ )
  trial = study.ask(fixed_distributions=search_space)
 
  self.logger.info(f"Asked trial {trial.number} with parameters {trial.params}.")

tests/test_cli.py

@@ -1166,6 +1166,9 @@ def test_ask(
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  args = [
  "optuna",
  "ask",
@@ -1218,6 +1221,9 @@ def test_ask_flatten(
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  args = [
  "optuna",
  "ask",
@@ -1261,6 +1267,9 @@ def test_ask_empty_search_space(output_format: str) -> None:
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  args = [
  "optuna",
  "ask",
@@ -1294,6 +1303,9 @@ def test_ask_empty_search_space_flatten(output_format: str) -> None:
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  args = [
  "optuna",
  "ask",
@@ -1331,6 +1343,9 @@ def test_ask_sampler_kwargs_without_sampler() -> None:
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  args = [
  "optuna",
  "ask",
@@ -1349,6 +1364,36 @@ def test_ask_sampler_kwargs_without_sampler() -> None:
  assert "`--sampler_kwargs` is set without `--sampler`." in error_message
 
 
+@pytest.mark.skip_coverage
+def test_ask_without_create_study_beforehand() -> None:
+ study_name = "test_study"
+ search_space = (
+ '{"x": {"name": "FloatDistribution", "attributes": {"low": 0.0, "high": 1.0}}, '
+ '"y": {"name": "CategoricalDistribution", "attributes": {"choices": ["foo"]}}}'
+ )
+
+ with NamedTemporaryFilePool() as tf:
+ db_url = "sqlite:///{}".format(tf.name)
+
+ args = [
+ "optuna",
+ "ask",
+ "--storage",
+ db_url,
+ "--study-name",
+ study_name,
+ "--search-space",
+ search_space,
+ ]
+
+ result = subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+ error_message = result.stderr.decode()
+ assert (
+ "Implicit study creation within the 'ask' command was dropped in Optuna v4.0.0."
+ in error_message
+ )
+
+
 @pytest.mark.skip_coverage
 @pytest.mark.parametrize(
  "direction,directions,sampler,sampler_kwargs",
@@ -1421,6 +1466,9 @@ def test_tell() -> None:
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  output: Any = subprocess.check_output(
  [
  "optuna",
@@ -1498,6 +1546,9 @@ def test_tell_with_nan() -> None:
  with NamedTemporaryFilePool() as tf:
  db_url = "sqlite:///{}".format(tf.name)
 
+ args = ["optuna", "create-study", "--storage", db_url, "--study-name", study_name]
+ subprocess.run(args, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
+
  output: Any = subprocess.check_output(
  [
  "optuna",