fix style for drex unittest

Author: ruoyuGao

ding/entry/tests/test_serial_entry_drex.py

@@ -0,0 +1,46 @@
+import pytest
+import os
+from easydict import EasyDict
+from copy import deepcopy
+
+from dizoo.classic_control.cartpole.config.cartpole_dqn_config \
+import cartpole_dqn_config, cartpole_dqn_create_config
+from dizoo.classic_control.cartpole.config.cartpole_drex_dqn_config \
+import cartpole_drex_dqn_config, cartpole_drex_dqn_create_config
+from ding.entry import serial_pipeline, serial_pipeline_reward_model_offpolicy
+from ding.entry.application_entry_drex_collect_data import drex_collecting_data
+
+
+@pytest.mark.unittest
+def test_drex():
+    exp_name = 'test_serial_pipeline_drex_expert'
+    config = [deepcopy(cartpole_dqn_config), deepcopy(cartpole_dqn_create_config)]
+    config[0].policy.learn.learner.hook.save_ckpt_after_iter = 100
+    config[0].exp_name = exp_name
+    expert_policy = serial_pipeline(config, seed=0)
+
+    exp_name = 'test_serial_pipeline_drex_collect'
+    config = [deepcopy(cartpole_drex_dqn_config), deepcopy(cartpole_drex_dqn_create_config)]
+    config[0].exp_name = exp_name
+    config[0].reward_model.exp_name = exp_name
+    config[0].reward_model.expert_model_path = 'test_serial_pipeline_drex_expert/ckpt/ckpt_best.pth.tar'
+    config[0].reward_model.reward_model_path = 'test_serial_pipeline_drex_collect/cartpole.params'
+    config[0].reward_model.offline_data_path = 'test_serial_pipeline_drex_collect'
+    config[0].reward_model.checkpoint_max = 100
+    config[0].reward_model.checkpoint_step = 100
+    config[0].reward_model.num_snippets = 100
+
+    args = EasyDict({'cfg': deepcopy(config), 'seed': 0, 'device': 'cpu'})
+    args.cfg[0].policy.collect.n_episode = 8
+    del args.cfg[0].policy.collect.n_sample
+    args.cfg[0].bc_iteration = 1000  # for unittest
+    args.cfg[1].policy.type = 'bc'
+    drex_collecting_data(args=args)
+    try:
+        serial_pipeline_reward_model_offpolicy(
+            config, seed=0, max_train_iter=1, pretrain_reward=True, cooptrain_reward=False
+        )
+    except Exception:
+        assert False, "pipeline fail"
+    finally:
+        os.popen('rm -rf test_serial_pipeline_drex*')