diff --git a/ding/example/dqn_nstep_envpool.py b/ding/example/dqn_nstep_envpool.py
index c5695f900f..7ab7a74677 100644
--- a/ding/example/dqn_nstep_envpool.py
+++ b/ding/example/dqn_nstep_envpool.py
@@ -80,10 +80,9 @@ def main(cfg):
                 cfg,
                 policy.collect_mode,
                 collector_env,
-                random_collect_size=cfg.policy.random_collect_size \
-                       if hasattr(cfg.policy, 'random_collect_size') else 0,
-                    )
-                )
+                random_collect_size=cfg.policy.random_collect_size if hasattr(cfg.policy, 'random_collect_size') else 0,
+            )
+        )
         task.use(data_pusher(cfg, buffer_))
         task.use(EnvpoolOffPolicyLearner(cfg, policy, buffer_))
         task.use(online_logger(train_show_freq=10))
diff --git a/ding/framework/middleware/collector.py b/ding/framework/middleware/collector.py
index d6a11bcb61..ed58c80993 100644
--- a/ding/framework/middleware/collector.py
+++ b/ding/framework/middleware/collector.py
@@ -187,7 +187,7 @@ def __call__(self, ctx: "OnlineRLContext") -> None:
                     )
 
                 if self._nsteps > 1:
-                    if done[i] == False and counter < target_size:
+                    if done[i] is False and counter < target_size:
                         reverse_record_position = min(self._nsteps, len(self._trajectory[env_id_receive[i]]))
                         real_reverse_record_position = reverse_record_position
 
@@ -195,7 +195,7 @@ def __call__(self, ctx: "OnlineRLContext") -> None:
                             if j == 1:
                                 pass
                             else:
-                                if self._trajectory[env_id_receive[i]][-j]['done'] == True:
+                                if self._trajectory[env_id_receive[i]][-j]['done'] is True:
                                     real_reverse_record_position = j - 1
                                     break
                                 else:
@@ -207,7 +207,7 @@ def __call__(self, ctx: "OnlineRLContext") -> None:
                             self._trajectory[env_id_receive[i]][-real_reverse_record_position][
                                 'value_gamma'] = self._discount_ratio_list[real_reverse_record_position - 1]
 
-                    else:  # done[i] == True or counter >= target_size
+                    else:  # done[i] is True or counter >= target_size
 
                         reverse_record_position = min(self._nsteps, len(self._trajectory[env_id_receive[i]]))
                         real_reverse_record_position = reverse_record_position
@@ -224,7 +224,7 @@ def __call__(self, ctx: "OnlineRLContext") -> None:
                                 self._trajectory[env_id_receive[i]][-j]['value_gamma'] = self._discount_ratio_list[j -
                                                                                                                    1]
                             else:
-                                if self._trajectory[env_id_receive[i]][-j]['done'] == True:
+                                if self._trajectory[env_id_receive[i]][-j]['done'] is True:
                                     real_reverse_record_position = j
                                     break
                                 else:
diff --git a/ding/framework/middleware/functional/data_processor.py b/ding/framework/middleware/functional/data_processor.py
index 420af3d4fd..e254e4ad3b 100644
--- a/ding/framework/middleware/functional/data_processor.py
+++ b/ding/framework/middleware/functional/data_processor.py
@@ -284,7 +284,6 @@ def offline_data_fetcher_from_mem(cfg: EasyDict, dataset: Dataset) -> Callable:
 
     from threading import Thread
     from queue import Queue
-    import time
     stream = torch.cuda.Stream()
 
     def producer(queue, dataset, batch_size, device):
diff --git a/ding/framework/middleware/functional/evaluator.py b/ding/framework/middleware/functional/evaluator.py
index 37093a3a67..31b70153a7 100644
--- a/ding/framework/middleware/functional/evaluator.py
+++ b/ding/framework/middleware/functional/evaluator.py
@@ -385,7 +385,7 @@ def _evaluate(ctx: Union["OnlineRLContext", "OfflineRLContext"]):
                     }
                 )
 
-                if done[i] == True:
+                if done[i] is True:
                     episode_return_i = 0.0
                     for item in trajectory[env_id_receive[i]]:
                         episode_return_i += item['reward'][0]
diff --git a/ding/framework/middleware/learner.py b/ding/framework/middleware/learner.py
index 7182a9d5df..8779ced315 100644
--- a/ding/framework/middleware/learner.py
+++ b/ding/framework/middleware/learner.py
@@ -36,11 +36,11 @@ def data_process_func(
             else:
                 output_data = fast_preprocess_learn(
                     data,
-                    use_priority=use_priority,  #policy._cfg.priority,
-                    use_priority_IS_weight=use_priority_IS_weight,  #policy._cfg.priority_IS_weight,
-                    use_nstep=use_nstep,  #policy._cfg.nstep > 1,
-                    cuda=cuda,  #policy._cuda,
-                    device=device,  #policy._device,
+                    use_priority=use_priority,
+                    use_priority_IS_weight=use_priority_IS_weight,
+                    use_nstep=use_nstep,
+                    cuda=cuda,
+                    device=device,
                 )
             data_queue_output.put(output_data)
 
diff --git a/ding/policy/common_utils.py b/ding/policy/common_utils.py
index 97a0084b37..a8e095974c 100644
--- a/ding/policy/common_utils.py
+++ b/ding/policy/common_utils.py
@@ -1,7 +1,6 @@
 from typing import List, Any, Dict, Callable
 import numpy as np
 import torch
-import numpy as np
 import treetensor.torch as ttorch
 from ding.utils.data import default_collate
 from ding.torch_utils import to_tensor, to_ndarray, unsqueeze, squeeze, to_device
@@ -82,7 +81,8 @@ def fast_preprocess_learn(
     Overview:
         Fast data pre-processing before policy's ``_forward_learn`` method, including stacking batch data, transform \
         data to PyTorch Tensor and move data to GPU, etc. This function is faster than ``default_preprocess_learn`` \
-        but less flexible. This function abandons calling ``default_collate`` to stack data because ``default_collate`` \
+        but less flexible.
+        This function abandons calling ``default_collate`` to stack data because ``default_collate`` \
         is recursive and cumbersome. In this function, we alternatively stack the data and send it to GPU, so that it \
         is faster. In addition, this function is usually used in a special data process thread in learner.
     Arguments: