ray/rllib/examples/custom_tf_policy.py
Sven 60d4d5e1aa Remove future imports (#6724)
* Remove all __future__ imports from RLlib.

* Remove (object) again from tf_run_builder.py::TFRunBuilder.

* Fix 2xLINT warnings.

* Fix broken appo_policy import (must be appo_tf_policy)

* Remove future imports from all other ray files (not just RLlib).

* Remove future imports from all other ray files (not just RLlib).

* Remove future import blocks that contain `unicode_literals` as well.
Revert appo_tf_policy.py to appo_policy.py (belongs to another PR).

* Add two empty lines before Schedule class.

* Put back __future__ imports into determine_tests_to_run.py. Fails otherwise on a py2/print related error.
2020-01-09 00:15:48 -08:00

53 lines
1.5 KiB
Python

import argparse
import ray
from ray import tune
from ray.rllib.agents.trainer_template import build_trainer
from ray.rllib.evaluation.postprocessing import discount
from ray.rllib.policy.tf_policy_template import build_tf_policy
from ray.rllib.utils import try_import_tf
tf = try_import_tf()
parser = argparse.ArgumentParser()
parser.add_argument("--iters", type=int, default=200)
def policy_gradient_loss(policy, model, dist_class, train_batch):
logits, _ = model.from_batch(train_batch)
action_dist = dist_class(logits, model)
return -tf.reduce_mean(
action_dist.logp(train_batch["actions"]) * train_batch["returns"])
def calculate_advantages(policy,
sample_batch,
other_agent_batches=None,
episode=None):
sample_batch["returns"] = discount(sample_batch["rewards"], 0.99)
return sample_batch
# <class 'ray.rllib.policy.tf_policy_template.MyTFPolicy'>
MyTFPolicy = build_tf_policy(
name="MyTFPolicy",
loss_fn=policy_gradient_loss,
postprocess_fn=calculate_advantages,
)
# <class 'ray.rllib.agents.trainer_template.MyCustomTrainer'>
MyTrainer = build_trainer(
name="MyCustomTrainer",
default_policy=MyTFPolicy,
)
if __name__ == "__main__":
ray.init()
args = parser.parse_args()
tune.run(
MyTrainer,
stop={"training_iteration": args.iters},
config={
"env": "CartPole-v0",
"num_workers": 2,
})