ray/rllib/examples/env/curriculum_capable_env.py

75 lines
2.7 KiB
Python

import gym
import random
from ray.rllib.env.apis.task_settable_env import TaskSettableEnv
from ray.rllib.env.env_context import EnvContext
from ray.rllib.utils.annotations import override
class CurriculumCapableEnv(TaskSettableEnv):
"""Example of a curriculum learning capable env.
This simply wraps a FrozenLake-v0 env and makes it harder with each
task. Task (difficulty levels) can range from 1 to 10."""
# Defining the different maps (all same size) for the different
# tasks. Theme here is to move the goal further and further away and
# to add more and more holes along the way.
MAPS = [
["SFFFFFF", "FFFFFFF", "FFFFFFF", "HHFFFFG", "FFFFFFF", "FFFFFFF"],
["SFFFFFF", "FFFHFFF", "FFFFFFF", "HHHFFFF", "FFFFFFG", "FFFFFFF"],
["SFFFFFF", "FFHHFFF", "FFFFFFF", "HHHHFFF", "FFFFFFF", "FFFFFFG"],
["SFFFFFF", "FHHHFFF", "FFFFFFF", "HHHHHFF", "FFFFFFF", "FFFFFGF"],
["SFFFFFF", "FFFHHFF", "FHFFFFF", "HHHHHHF", "FFHFFHF", "FFFGFFF"],
]
def __init__(self, config: EnvContext):
self.cur_level = config.get("start_level", 1)
self.max_timesteps = config.get("max_timesteps", 18)
self.frozen_lake = None
self._make_lake() # create self.frozen_lake
self.observation_space = self.frozen_lake.observation_space
self.action_space = self.frozen_lake.action_space
self.switch_env = False
self._timesteps = 0
def reset(self):
if self.switch_env:
self.switch_env = False
self._make_lake()
self._timesteps = 0
return self.frozen_lake.reset()
def step(self, action):
self._timesteps += 1
s, r, d, i = self.frozen_lake.step(action)
# Make rewards scale with the level exponentially:
# Level 1: x1
# Level 2: x10
# Level 3: x100, etc..
r *= 10**(self.cur_level - 1)
if self._timesteps >= self.max_timesteps:
d = True
return s, r, d, i
@override(TaskSettableEnv)
def sample_tasks(self, n_tasks):
"""Implement this to sample n random tasks."""
return [random.randint(1, 10) for _ in range(n_tasks)]
@override(TaskSettableEnv)
def get_task(self):
"""Implement this to get the current task (curriculum level)."""
return self.cur_level
@override(TaskSettableEnv)
def set_task(self, task):
"""Implement this to set the task (curriculum level) for this env."""
self.cur_level = task
self.switch_env = True
def _make_lake(self):
self.frozen_lake = gym.make(
"FrozenLake-v0",
desc=self.MAPS[self.cur_level - 1],
is_slippery=False)