class maze.core.wrappers.log_stats_wrapper.LogStatsWrapper(*args, **kwds)

A statistics logging wrapper for BaseEnv.


env – The environment to wrap.


(overrides LogStatsEnv)

Implementation of the LogStatsEnv interface, clear out episode statistics collected so far in this epoch.

clone_from(env: maze.core.wrappers.log_stats_wrapper.LogStatsWrapper)None

(overrides SimulatedEnvMixin)

implementation of SimulatedEnvMixin.


(overrides BaseEnv)

Close the stats rendering figure if needed.

get_last_step_events(query: Union[Callable, Iterable[Callable]] = None)

Convenience accessor to all events recorded during the last step.


query – Specify which events to return (one or more interface methods)


Recorded events from the last step (all if no query is present)

get_observation_and_action_dicts(maze_state: Optional[Any], maze_action: Optional[Any], first_step_in_episode: bool) → Tuple[Optional[Dict[Union[int, str], Any]], Optional[Dict[Union[int, str], Any]]]

(overrides Wrapper)

Keep both actions and observation the same.

get_stats(level: maze.core.log_stats.log_stats.LogStatsLevel)maze.core.log_stats.log_stats.LogStatsAggregator

(overrides LogStatsEnv)

Implementation of the LogStatsEnv interface, return the statistics aggregator.

get_stats_value(event: Callable, level: maze.core.log_stats.log_stats.LogStatsLevel, name: Optional[str] = None) → Union[int, float, numpy.ndarray, dict]

(overrides LogStatsEnv)

Implementation of the LogStatsEnv interface, obtain the value from the cached aggregator statistics.

render_stats(event_name: str = 'BaseEnvEvents.reward', metric_name: str = 'value', aggregation_func: Optional[Union[str, Callable]] = None, group_by: str = None, post_processing_func: Optional[Union[str, Callable]] = 'cumsum')

Render statistics from the currently running episode.

Rendering is based on event logs. You can select arbitrary events from those dispatched by the currently running environment.

  • event_name – Name of the even the even log corresponds to

  • metric_name – Metric to use (one of the event attributes, e.g. “n_items” – depends on the event type)

  • aggregation_func – Optionally, specifies how to aggregate the metric on step level, i.e. when there are multiple same events dispatched during the same step.

  • group_by – Optionally, another of event attributes to group by on the step level (e.g. “product_id”)

  • post_processing_func – Optionally, a function to post-process the data (“cumsum” is often used)

reset() → Any

(overrides BaseEnv)

Reset the environment and trigger the episode statistics calculation of the previous run.

step(action: Any) → Tuple[Any, Any, bool, Dict[Any, Any]]

(overrides BaseEnv)

Collect the rewards for the logging statistics

classmethod wrap(env: T, logging_prefix: Optional[str] = None) → Union[T, maze.core.log_stats.log_stats_env.LogStatsEnv]

Creation method providing appropriate type hints. Preferred method to construct the wrapper compared to calling the class constructor directly.

  • env – The environment to be wrapped.

  • logging_prefix – The episode statistics is connected to the logging system with this tagging prefix. If None, no logging happens.

:return A newly created wrapper instance.


(overrides LogStatsEnv)

Implementation of the LogStatsEnv interface, call reduce on the episode aggregator.