trackedenv.py

    def best_sequence(self):
        """
        Get the prefix of the trajectory with the best
        cumulative reward.
        """
        max_cumulative = max(self.reward_history)
        for i, rew in enumerate(self.reward_history):
            if rew == max_cumulative:
                return self.action_history[:i+1]
        raise RuntimeError('unreachable')

    # pylint: disable=E0202
    def reset(self, **kwargs):
        self.action_history = []
        self.reward_history = []
        self.total_reward = 0
        return self.env.reset(**kwargs)

    def step(self, action):
        self.total_steps_ever += 1
        self.action_history.append(action.copy())
        obs, rew, done, info = self.env.step(action)
        self.total_reward += rew
        self.reward_history.append(self.total_reward)
        return obs, rew, done, info