fix types and docstrings

rasa/core/policies/ensemble.py

@@ -723,7 +723,7 @@ def probabilities_using_best_policy(
                 domain, prediction.probabilities, policy_name
             )
 
-        logger.debug(f"Predicted next action using {policy_name}")
+        logger.debug(f"Predicted next action using {policy_name}.")
         return prediction.probabilities, policy_name
 
 

rasa/core/policies/sklearn_policy.py

@@ -281,7 +281,7 @@ def predict_action_probabilities(
         )
 
     def persist(self, path: Union[Text, Path]) -> None:
-        """Persist the policy properties (see parent class for more information)."""
+        """Persists the policy properties (see parent class for more information)."""
         if self.model:
             self.featurizer.persist(path)
 

rasa/core/policies/ted_policy.py

@@ -373,12 +373,14 @@ def predict_action_probabilities(
         interpreter: NaturalLanguageInterpreter,
         **kwargs: Any,
     ) -> PolicyPrediction:
-        """Predict the next action the bot should take.
+        """Predicts the next action the bot should take.
 
-        Return the list of probabilities for the next actions.
+        See the docstring of the parent class `Policy` for more information.
         """
         if self.model is None:
-            return PolicyPrediction(self._default_predictions(domain))
+            return PolicyPrediction(
+                self._default_predictions(domain), policy_priority=self.priority
+            )
 
         # create model data from tracker
         tracker_state_features = self.featurizer.create_state_features(

tests/core/test_ensemble.py

@@ -76,8 +76,8 @@ def test_policy_loading_simple(tmp_path: Path):
 class ConstantPolicy(Policy):
     def __init__(
         self,
-        priority: int = None,
-        predict_index: int = None,
+        priority: Optional[int] = None,
+        predict_index: Optional[int] = None,
         confidence: float = 1,
         is_end_to_end_prediction: bool = False,
         events: Optional[List[Event]] = None,