Check Action Type

hill-a#707

stable_baselines/common/vec_env/base_vec_env.py

@@ -146,6 +146,7 @@ def step(self, actions):
         :param actions: ([int] or [float]) the action
         :return: ([int] or [float], [float], [bool], dict) observation, reward, done, information
         """
+        assert isinstance( actions, ( list, np.ndarray ) ), "Action must be of type list or np.ndarray. Try wrapping your action variable in a list [ ] to fix this issue."
         self.step_async(actions)
         return self.step_wait()