import gym
try:
import pybullet_envs
import time
except ImportError:
pass
from gym import spaces as gym_spaces
from mushroom_rl.environments import Environment, MDPInfo
from mushroom_rl.utils.spaces import *
[docs]class Gym(Environment):
"""
Interface for OpenAI Gym environments. It makes it possible to use every
Gym environment just providing the id, except for the Atari games that
are managed in a separate class.
"""
[docs] def __init__(self, name, horizon, gamma):
"""
Constructor.
Args:
name (str): gym id of the environment;
horizon (int): the horizon;
gamma (float): the discount factor.
"""
# MDP creation
self._close_at_stop = True
if '- ' + name in pybullet_envs.getList():
import pybullet
pybullet.connect(pybullet.DIRECT)
self._close_at_stop = False
self.env = gym.make(name)
self.env._max_episode_steps = np.inf # Hack to ignore gym time limit.
# MDP properties
assert not isinstance(self.env.observation_space,
gym_spaces.MultiDiscrete)
assert not isinstance(self.env.action_space, gym_spaces.MultiDiscrete)
action_space = self._convert_gym_space(self.env.action_space)
observation_space = self._convert_gym_space(self.env.observation_space)
mdp_info = MDPInfo(observation_space, action_space, gamma, horizon)
if isinstance(action_space, Discrete):
self._convert_action = lambda a: a[0]
else:
self._convert_action = lambda a: a
super().__init__(mdp_info)
[docs] def reset(self, state=None):
if state is None:
return self.env.reset()
else:
self.env.reset()
self.env.state = state
return state
[docs] def step(self, action):
action = self._convert_action(action)
return self.env.step(action)
def render(self, mode='human'):
self.env.render(mode=mode)
[docs] def stop(self):
try:
if self._close_at_stop:
self.env.close()
except:
pass
@staticmethod
def _convert_gym_space(space):
if isinstance(space, gym_spaces.Discrete):
return Discrete(space.n)
elif isinstance(space, gym_spaces.Box):
return Box(low=space.low, high=space.high, shape=space.shape)
else:
raise ValueError