Monitor Wrapper

class stable_baselines3.common.monitor.Monitor(env, filename=None, allow_early_resets=True, reset_keywords=(), info_keywords=(), override_existing=True)

A monitor wrapper for Gym environments, it is used to know the episode reward, length, time and other data.

Parameters:

• env (Env) – The environment

• filename (Optional[str]) – the location to save a log file, can be None for no log

• allow_early_resets (bool) – allows the reset of the environment before it is done

• reset_keywords (Tuple[str, ...]) – extra keywords for the reset call, if extra parameters are needed at reset

• info_keywords (Tuple[str, ...]) – extra information to log, from the information return of env.step()

• override_existing (bool) – appends to file if filename exists, otherwise override existing files (default)

close()

Closes the environment

Return type:

None

get_episode_lengths()

Returns the number of timesteps of all the episodes

Return type:

List[int]

Returns:

get_episode_rewards()

Returns the rewards of all the episodes

Return type:

List[float]

Returns:

get_episode_times()

Returns the runtime in seconds of all the episodes

Return type:

List[float]

Returns:

get_total_steps()

Returns the total number of timesteps

Return type:

int

Returns:

reset(**kwargs)

Calls the Gym environment reset. Can only be called if the environment is over, or if allow_early_resets is True

Parameters:

kwargs – Extra keywords saved for the next episode. only if defined by reset_keywords

Return type:

Tuple[TypeVar(ObsType), Dict[str, Any]]

Returns:

the first observation of the environment

step(action)

Step the environment with the given action

Parameters:

action (TypeVar(ActType)) – the action

Return type:

Tuple[TypeVar(ObsType), SupportsFloat, bool, bool, Dict[str, Any]]

Returns:

observation, reward, terminated, truncated, information

class stable_baselines3.common.monitor.ResultsWriter(filename='', header=None, extra_keys=(), override_existing=True)

A result writer that saves the data from the Monitor class

Parameters:

• filename (str) – the location to save a log file. When it does not end in the string "monitor.csv", this suffix will be appended to it

• header (Optional[Dict[str, Union[float, str]]]) – the header dictionary object of the saved csv

• extra_keys (Tuple[str, ...]) – the extra information to log, typically is composed of reset_keywords and info_keywords

• override_existing (bool) – appends to file if filename exists, otherwise override existing files (default)

close()

Close the file handler

Return type:

None

write_row(epinfo)

Write row of monitor data to csv log file.

Parameters:

epinfo (Dict[str, float]) – the information on episodic return, length, and time

Return type:

None

stable_baselines3.common.monitor.get_monitor_files(path)

get all the monitor files in the given path

Parameters:

path (str) – the logging folder

Return type:

List[str]

Returns:

the log files

stable_baselines3.common.monitor.load_results(path)

Load all Monitor logs from a given directory path matching *monitor.csv

Parameters:

path (str) – the directory path containing the log file(s)

Return type:

DataFrame

Returns:

the logged data