training_env is a property, also, so types can't be overridden

freqtrade/freqai/tensorboard/TensorboardCallback.py

@@ -3,7 +3,6 @@ from typing import Any, Dict, Type, Union
 
 from stable_baselines3.common.callbacks import BaseCallback
 from stable_baselines3.common.logger import HParam
-from stable_baselines3.common.vec_env import VecEnv
 
 from freqtrade.freqai.RL.BaseEnvironment import BaseActions
 
@@ -13,9 +12,6 @@ class TensorboardCallback(BaseCallback):
     Custom callback for plotting additional values in tensorboard and
     episodic summary reports.
     """
-    # Override training_env type to fix type errors
-    training_env: Union[VecEnv, None] = None
-
     def __init__(self, verbose=1, actions: Type[Enum] = BaseActions):
         super().__init__(verbose)
         self.model: Any = None
@@ -46,8 +42,6 @@ class TensorboardCallback(BaseCallback):
     def _on_step(self) -> bool:
 
         local_info = self.locals["infos"][0]
-        if self.training_env is None:
-            return True
 
         if hasattr(self.training_env, 'envs'):
             tensorboard_metrics = self.training_env.envs[0].unwrapped.tensorboard_metrics