diff --git a/stable_baselines3/a2c/__init__.py b/stable_baselines3/a2c/__init__.py
index 78fc54fb1..67f58df35 100644
--- a/stable_baselines3/a2c/__init__.py
+++ b/stable_baselines3/a2c/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.a2c.a2c import A2C
 from stable_baselines3.a2c.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "A2C"]
+__all__ = ["A2C", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]
diff --git a/stable_baselines3/common/save_util.py b/stable_baselines3/common/save_util.py
index 8b545f898..3da23451b 100644
--- a/stable_baselines3/common/save_util.py
+++ b/stable_baselines3/common/save_util.py
@@ -216,7 +216,7 @@ def open_path(
         mode = {"write": "w", "read": "r", "w": "w", "r": "r"}[mode]
     except KeyError as e:
         raise ValueError("Expected mode to be either 'w' or 'r'.") from e
-    if ("w" == mode) and not path.writable() or ("r" == mode) and not path.readable():
+    if (("w" == mode) and not path.writable()) or (("r" == mode) and not path.readable()):
         error_msg = "writable" if "w" == mode else "readable"
         raise ValueError(f"Expected a {error_msg} file.")
     return path
diff --git a/stable_baselines3/common/vec_env/__init__.py b/stable_baselines3/common/vec_env/__init__.py
index 9a60c07dc..ac49a0469 100644
--- a/stable_baselines3/common/vec_env/__init__.py
+++ b/stable_baselines3/common/vec_env/__init__.py
@@ -86,20 +86,20 @@ def sync_envs_normalization(env: VecEnv, eval_env: VecEnv) -> None:
 
 __all__ = [
     "CloudpickleWrapper",
-    "VecEnv",
-    "VecEnvWrapper",
     "DummyVecEnv",
     "StackedObservations",
     "SubprocVecEnv",
     "VecCheckNan",
+    "VecEnv",
+    "VecEnvWrapper",
     "VecExtractDictObs",
     "VecFrameStack",
     "VecMonitor",
     "VecNormalize",
     "VecTransposeImage",
     "VecVideoRecorder",
-    "unwrap_vec_wrapper",
-    "unwrap_vec_normalize",
     "is_vecenv_wrapped",
     "sync_envs_normalization",
+    "unwrap_vec_normalize",
+    "unwrap_vec_wrapper",
 ]
diff --git a/stable_baselines3/ddpg/__init__.py b/stable_baselines3/ddpg/__init__.py
index 257a3e3a5..6071aaad4 100644
--- a/stable_baselines3/ddpg/__init__.py
+++ b/stable_baselines3/ddpg/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.ddpg.ddpg import DDPG
 from stable_baselines3.ddpg.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "DDPG"]
+__all__ = ["DDPG", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]
diff --git a/stable_baselines3/dqn/__init__.py b/stable_baselines3/dqn/__init__.py
index 2e5e2db96..006b6dc0a 100644
--- a/stable_baselines3/dqn/__init__.py
+++ b/stable_baselines3/dqn/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.dqn.dqn import DQN
 from stable_baselines3.dqn.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "DQN"]
+__all__ = ["DQN", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]
diff --git a/stable_baselines3/ppo/__init__.py b/stable_baselines3/ppo/__init__.py
index cd91257b5..068347b00 100644
--- a/stable_baselines3/ppo/__init__.py
+++ b/stable_baselines3/ppo/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.ppo.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 from stable_baselines3.ppo.ppo import PPO
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "PPO"]
+__all__ = ["PPO", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]
diff --git a/stable_baselines3/sac/__init__.py b/stable_baselines3/sac/__init__.py
index bdf780d43..b4fd59ebe 100644
--- a/stable_baselines3/sac/__init__.py
+++ b/stable_baselines3/sac/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.sac.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 from stable_baselines3.sac.sac import SAC
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "SAC"]
+__all__ = ["SAC", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]
diff --git a/stable_baselines3/td3/__init__.py b/stable_baselines3/td3/__init__.py
index 428141e5c..efdfc9fa8 100644
--- a/stable_baselines3/td3/__init__.py
+++ b/stable_baselines3/td3/__init__.py
@@ -1,4 +1,4 @@
 from stable_baselines3.td3.policies import CnnPolicy, MlpPolicy, MultiInputPolicy
 from stable_baselines3.td3.td3 import TD3
 
-__all__ = ["CnnPolicy", "MlpPolicy", "MultiInputPolicy", "TD3"]
+__all__ = ["TD3", "CnnPolicy", "MlpPolicy", "MultiInputPolicy"]