def logs(self, prefix='worker'):
        """Generates a dictionary that contains all collected statistics.
        """
        logs = []
        logs += [('success_rate', np.mean(self.success_history))]
        if self.compute_Q:
            logs += [('mean_Q', np.mean(self.Q_history))]
        logs += [('episode', self.n_episodes)]

        if prefix != '' and not prefix.endswith('/'):
            return [(prefix + '/' + key, val) for key, val in logs]
        else:
            return logs
Generates a dictionary that contains all collected statistics.