ray/rllib/examples/sb2rllib_rllib_example.py
xwjiang2010 fcf897ee72
[air] update rllib example to use Tuner API. (#26987)
update rllib example to use Tuner API.

Signed-off-by: xwjiang2010 <xwjiang2010@gmail.com>
2022-07-27 12:12:59 +01:00

50 lines
1.4 KiB
Python

"""
Example script on how to train, save, load, and test an RLlib agent.
Equivalent script with stable baselines: sb2rllib_sb_example.py.
Demonstrates transition from stable_baselines to Ray RLlib.
Run example: python sb2rllib_rllib_example.py
"""
import gym
from ray import tune, air
import ray.rllib.algorithms.ppo as ppo
# settings used for both stable baselines and rllib
env_name = "CartPole-v1"
train_steps = 10000
learning_rate = 1e-3
save_dir = "saved_models"
# training and saving
analysis = tune.Tuner(
"PPO",
run_config=air.RunConfig(
stop={"timesteps_total": train_steps},
local_dir=save_dir,
checkpoint_config=air.CheckpointConfig(
checkpoint_at_end=True,
),
),
param_space={"env": env_name, "lr": learning_rate},
).fit()
# retrieve the checkpoint path
analysis.default_metric = "episode_reward_mean"
analysis.default_mode = "max"
checkpoint_path = analysis.get_best_checkpoint(trial=analysis.get_best_trial())
print(f"Trained model saved at {checkpoint_path}")
# load and restore model
agent = ppo.PPO(env=env_name)
agent.restore(checkpoint_path)
print(f"Agent loaded from saved model at {checkpoint_path}")
# inference
env = gym.make(env_name)
obs = env.reset()
for i in range(1000):
action = agent.compute_single_action(obs)
obs, reward, done, info = env.step(action)
env.render()
if done:
print(f"Cart pole dropped after {i} steps.")
break