Fix inline types

Author: araffin

stable_baselines3/common/base_class.py

@@ -142,10 +142,10 @@ def __init__(
         self.start_time = 0.0
         self.learning_rate = learning_rate
         self.tensorboard_log = tensorboard_log
-        self._last_obs = None  # type: Optional[Union[np.ndarray, dict[str, np.ndarray]]]
-        self._last_episode_starts = None  # type: Optional[np.ndarray]
+        self._last_obs = None  # type: np.ndarray | dict[str, np.ndarray] | None
+        self._last_episode_starts = None  # type: np.ndarray | None
         # When using VecNormalize:
-        self._last_original_obs = None  # type: Optional[Union[np.ndarray, dict[str, np.ndarray]]]
+        self._last_original_obs = None  # type: np.ndarray | dict[str, np.ndarray] | None
         self._episode_num = 0
         # Used for gSDE only
         self.use_sde = use_sde
@@ -155,8 +155,8 @@ def __init__(
         self._current_progress_remaining = 1.0
         # Buffers for logging
         self._stats_window_size = stats_window_size
-        self.ep_info_buffer = None  # type: Optional[deque]
-        self.ep_success_buffer = None  # type: Optional[deque]
+        self.ep_info_buffer = None  # type: deque | None
+        self.ep_success_buffer = None  # type: deque | None
         # For logging (and TD3 delayed updates)
         self._n_updates = 0  # type: int
         # Whether the user passed a custom logger or not

stable_baselines3/common/callbacks.py

@@ -50,7 +50,7 @@ def __init__(self, verbose: int = 0):
         self.globals: dict[str, Any] = {}
         # Sometimes, for event callback, it is useful
         # to have access to the parent object
-        self.parent = None  # type: Optional[BaseCallback]
+        self.parent = None  # type: BaseCallback | None
 
     @property
     def training_env(self) -> VecEnv:

stable_baselines3/common/vec_env/stacked_observations.py

@@ -43,7 +43,7 @@ def __init__(
             }
             self.stacked_observation_space = spaces.Dict(
                 {key: substack_obs.stacked_observation_space for key, substack_obs in self.sub_stacked_observations.items()}
-            )  # type: Union[spaces.Dict, spaces.Box] # make mypy happy
+            )  # type: spaces.Dict | spaces.Box # make mypy happy
         elif isinstance(observation_space, spaces.Box):
             if isinstance(channels_order, Mapping):
                 raise TypeError("When the observation space is Box, channels_order can't be a dict.")

stable_baselines3/sac/sac.py

@@ -149,7 +149,7 @@ def __init__(
         )
 
         self.target_entropy = target_entropy
-        self.log_ent_coef = None  # type: Optional[th.Tensor]
+        self.log_ent_coef = None  # type: th.Tensor | None
         # Entropy coefficient / Entropy temperature
         # Inverse of the reward scale
         self.ent_coef = ent_coef