__all__ = ["Monitor", "get_monitor_files", "load_results"]
import csv
import json
import os
import time
from glob import glob
from typing import List, Optional, Tuple, Union
import gym
import numpy as np
import pandas
from stable_baselines3.common.type_aliases import GymObs, GymStepReturn
[docs]class Monitor(gym.Wrapper):
"""
A monitor wrapper for Gym environments, it is used to know the episode reward, length, time and other data.
:param env: The environment
:param filename: the location to save a log file, can be None for no log
:param allow_early_resets: allows the reset of the environment before it is done
:param reset_keywords: extra keywords for the reset call,
if extra parameters are needed at reset
:param info_keywords: extra information to log, from the information return of env.step()
"""
EXT = "monitor.csv"
def __init__(
self,
env: gym.Env,
filename: Optional[str] = None,
allow_early_resets: bool = True,
reset_keywords: Tuple[str, ...] = (),
info_keywords: Tuple[str, ...] = (),
):
super(Monitor, self).__init__(env=env)
self.t_start = time.time()
if filename is None:
self.file_handler = None
self.logger = None
else:
if not filename.endswith(Monitor.EXT):
if os.path.isdir(filename):
filename = os.path.join(filename, Monitor.EXT)
else:
filename = filename + "." + Monitor.EXT
self.file_handler = open(filename, "wt")
self.file_handler.write("#%s\n" % json.dumps({"t_start": self.t_start, "env_id": env.spec and env.spec.id}))
self.logger = csv.DictWriter(self.file_handler, fieldnames=("r", "l", "t") + reset_keywords + info_keywords)
self.logger.writeheader()
self.file_handler.flush()
self.reset_keywords = reset_keywords
self.info_keywords = info_keywords
self.allow_early_resets = allow_early_resets
self.rewards = None
self.needs_reset = True
self.episode_rewards = []
self.episode_lengths = []
self.episode_times = []
self.total_steps = 0
self.current_reset_info = {} # extra info about the current episode, that was passed in during reset()
[docs] def reset(self, **kwargs) -> GymObs:
"""
Calls the Gym environment reset. Can only be called if the environment is over, or if allow_early_resets is True
:param kwargs: Extra keywords saved for the next episode. only if defined by reset_keywords
:return: the first observation of the environment
"""
if not self.allow_early_resets and not self.needs_reset:
raise RuntimeError(
"Tried to reset an environment before done. If you want to allow early resets, "
"wrap your env with Monitor(env, path, allow_early_resets=True)"
)
self.rewards = []
self.needs_reset = False
for key in self.reset_keywords:
value = kwargs.get(key)
if value is None:
raise ValueError("Expected you to pass kwarg {} into reset".format(key))
self.current_reset_info[key] = value
return self.env.reset(**kwargs)
[docs] def step(self, action: Union[np.ndarray, int]) -> GymStepReturn:
"""
Step the environment with the given action
:param action: the action
:return: observation, reward, done, information
"""
if self.needs_reset:
raise RuntimeError("Tried to step environment that needs reset")
observation, reward, done, info = self.env.step(action)
self.rewards.append(reward)
if done:
self.needs_reset = True
ep_rew = sum(self.rewards)
ep_len = len(self.rewards)
ep_info = {"r": round(ep_rew, 6), "l": ep_len, "t": round(time.time() - self.t_start, 6)}
for key in self.info_keywords:
ep_info[key] = info[key]
self.episode_rewards.append(ep_rew)
self.episode_lengths.append(ep_len)
self.episode_times.append(time.time() - self.t_start)
ep_info.update(self.current_reset_info)
if self.logger:
self.logger.writerow(ep_info)
self.file_handler.flush()
info["episode"] = ep_info
self.total_steps += 1
return observation, reward, done, info
[docs] def close(self) -> None:
"""
Closes the environment
"""
super(Monitor, self).close()
if self.file_handler is not None:
self.file_handler.close()
[docs] def get_total_steps(self) -> int:
"""
Returns the total number of timesteps
:return:
"""
return self.total_steps
[docs] def get_episode_rewards(self) -> List[float]:
"""
Returns the rewards of all the episodes
:return:
"""
return self.episode_rewards
[docs] def get_episode_lengths(self) -> List[int]:
"""
Returns the number of timesteps of all the episodes
:return:
"""
return self.episode_lengths
[docs] def get_episode_times(self) -> List[float]:
"""
Returns the runtime in seconds of all the episodes
:return:
"""
return self.episode_times
class LoadMonitorResultsError(Exception):
"""
Raised when loading the monitor log fails.
"""
pass
[docs]def get_monitor_files(path: str) -> List[str]:
"""
get all the monitor files in the given path
:param path: the logging folder
:return: the log files
"""
return glob(os.path.join(path, "*" + Monitor.EXT))
[docs]def load_results(path: str) -> pandas.DataFrame:
"""
Load all Monitor logs from a given directory path matching ``*monitor.csv``
:param path: the directory path containing the log file(s)
:return: the logged data
"""
monitor_files = get_monitor_files(path)
if len(monitor_files) == 0:
raise LoadMonitorResultsError(f"No monitor files of the form *{Monitor.EXT} found in {path}")
data_frames, headers = [], []
for file_name in monitor_files:
with open(file_name, "rt") as file_handler:
first_line = file_handler.readline()
assert first_line[0] == "#"
header = json.loads(first_line[1:])
data_frame = pandas.read_csv(file_handler, index_col=None)
headers.append(header)
data_frame["t"] += header["t_start"]
data_frames.append(data_frame)
data_frame = pandas.concat(data_frames)
data_frame.sort_values("t", inplace=True)
data_frame.reset_index(inplace=True)
data_frame["t"] -= min(header["t_start"] for header in headers)
return data_frame