diff --git a/examples/other/1xt2x/src_deepspeech2x/models/ds2/deepspeech2.py b/examples/other/1xt2x/src_deepspeech2x/models/ds2/deepspeech2.py
index 003b02e2..e25e4030 100644
--- a/examples/other/1xt2x/src_deepspeech2x/models/ds2/deepspeech2.py
+++ b/examples/other/1xt2x/src_deepspeech2x/models/ds2/deepspeech2.py
@@ -12,12 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Deepspeech2 ASR Model"""
-from typing import Optional
-
 import paddle
 from paddle import nn
 from src_deepspeech2x.models.ds2.rnn import RNNStack
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.models.ds2.conv import ConvStack
 from paddlespeech.s2t.modules.ctc import CTCDecoder
diff --git a/examples/other/1xt2x/src_deepspeech2x/test_model.py b/examples/other/1xt2x/src_deepspeech2x/test_model.py
index 246fb107..2a38fb5c 100644
--- a/examples/other/1xt2x/src_deepspeech2x/test_model.py
+++ b/examples/other/1xt2x/src_deepspeech2x/test_model.py
@@ -15,8 +15,6 @@
 import time
 from collections import defaultdict
 from contextlib import nullcontext
-from pathlib import Path
-from typing import Optional
 
 import numpy as np
 import paddle
@@ -24,7 +22,6 @@ from paddle import distributed as dist
 from paddle.io import DataLoader
 from src_deepspeech2x.models.ds2 import DeepSpeech2InferModel
 from src_deepspeech2x.models.ds2 import DeepSpeech2Model
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
 from paddlespeech.s2t.io.collator import SpeechCollator
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/deploy/runtime.py b/paddlespeech/s2t/exps/deepspeech2/bin/deploy/runtime.py
index ccb85906..5755a5f1 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/deploy/runtime.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/deploy/runtime.py
@@ -19,8 +19,8 @@ import paddle
 from paddle.inference import Config
 from paddle.inference import create_predictor
 from paddle.io import DataLoader
-
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.io.collator import SpeechCollator
 from paddlespeech.s2t.io.dataset import ManifestDataset
 from paddlespeech.s2t.models.ds2 import DeepSpeech2Model
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/deploy/server.py b/paddlespeech/s2t/exps/deepspeech2/bin/deploy/server.py
index 85c2466f..0d0b4f21 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/deploy/server.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/deploy/server.py
@@ -17,8 +17,8 @@ import functools
 import numpy as np
 import paddle
 from paddle.io import DataLoader
-
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.io.collator import SpeechCollator
 from paddlespeech.s2t.io.dataset import ManifestDataset
 from paddlespeech.s2t.models.ds2 import DeepSpeech2Model
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/export.py b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
index 090b5fab..ee013d79 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/export.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Export for DeepSpeech2 model."""
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.deepspeech2.model import DeepSpeech2Tester as Tester
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
index 176028ed..707eb9e1 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test_export.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Evaluation for DeepSpeech2 model."""
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.deepspeech2.model import DeepSpeech2ExportTester as ExportTester
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py b/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
index e2cb7e2f..a909dd41 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/test_wav.py
@@ -20,7 +20,6 @@ import paddle
 import soundfile
 from yacs.config import CfgNode
 
-from paddlespeech.s2t.exps.deepspeech2.config import get_cfg_defaults
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
 from paddlespeech.s2t.io.collator import SpeechCollator
 from paddlespeech.s2t.models.ds2 import DeepSpeech2Model
diff --git a/paddlespeech/s2t/exps/deepspeech2/bin/train.py b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
index 5e8c0fff..09e8662f 100644
--- a/paddlespeech/s2t/exps/deepspeech2/bin/train.py
+++ b/paddlespeech/s2t/exps/deepspeech2/bin/train.py
@@ -13,8 +13,8 @@
 # limitations under the License.
 """Trainer for DeepSpeech2 model."""
 from paddle import distributed as dist
-
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.deepspeech2.model import DeepSpeech2Trainer as Trainer
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/deepspeech2/model.py b/paddlespeech/s2t/exps/deepspeech2/model.py
index e7d5e20f..049311c7 100644
--- a/paddlespeech/s2t/exps/deepspeech2/model.py
+++ b/paddlespeech/s2t/exps/deepspeech2/model.py
@@ -16,7 +16,6 @@ import os
 import time
 from collections import defaultdict
 from contextlib import nullcontext
-from typing import Optional
 
 import jsonlines
 import numpy as np
@@ -24,7 +23,6 @@ import paddle
 from paddle import distributed as dist
 from paddle import inference
 from paddle.io import DataLoader
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.featurizer.text_featurizer import TextFeaturizer
 from paddlespeech.s2t.io.collator import SpeechCollator
diff --git a/paddlespeech/s2t/exps/u2/bin/export.py b/paddlespeech/s2t/exps/u2/bin/export.py
index 3907cebd..592b1237 100644
--- a/paddlespeech/s2t/exps/u2/bin/export.py
+++ b/paddlespeech/s2t/exps/u2/bin/export.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Export for U2 model."""
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.u2.model import U2Tester as Tester
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/u2/bin/train.py b/paddlespeech/s2t/exps/u2/bin/train.py
index d562278f..53c22328 100644
--- a/paddlespeech/s2t/exps/u2/bin/train.py
+++ b/paddlespeech/s2t/exps/u2/bin/train.py
@@ -16,8 +16,8 @@ import cProfile
 import os
 
 from paddle import distributed as dist
-
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.u2.model import U2Trainer as Trainer
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/u2/model.py b/paddlespeech/s2t/exps/u2/model.py
index d0cea031..6ab671ee 100644
--- a/paddlespeech/s2t/exps/u2/model.py
+++ b/paddlespeech/s2t/exps/u2/model.py
@@ -18,13 +18,11 @@ import time
 from collections import defaultdict
 from collections import OrderedDict
 from contextlib import nullcontext
-from typing import Optional
 
 import jsonlines
 import numpy as np
 import paddle
 from paddle import distributed as dist
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.featurizer import TextFeaturizer
 from paddlespeech.s2t.io.dataloader import BatchDataLoader
diff --git a/paddlespeech/s2t/exps/u2_kaldi/model.py b/paddlespeech/s2t/exps/u2_kaldi/model.py
index 780c5c08..bc995977 100644
--- a/paddlespeech/s2t/exps/u2_kaldi/model.py
+++ b/paddlespeech/s2t/exps/u2_kaldi/model.py
@@ -17,13 +17,11 @@ import os
 import time
 from collections import defaultdict
 from contextlib import nullcontext
-from typing import Optional
 
 import jsonlines
 import numpy as np
 import paddle
 from paddle import distributed as dist
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.featurizer import TextFeaturizer
 from paddlespeech.s2t.frontend.utility import load_dict
@@ -42,6 +40,7 @@ from paddlespeech.s2t.utils.utility import UpdateConfig
 
 logger = Log(__name__).getlog()
 
+
 class U2Trainer(Trainer):
     def __init__(self, config, args):
         super().__init__(config, args)
diff --git a/paddlespeech/s2t/exps/u2_st/bin/export.py b/paddlespeech/s2t/exps/u2_st/bin/export.py
index 1bc4e1f3..c641152f 100644
--- a/paddlespeech/s2t/exps/u2_st/bin/export.py
+++ b/paddlespeech/s2t/exps/u2_st/bin/export.py
@@ -13,6 +13,7 @@
 # limitations under the License.
 """Export for U2 model."""
 from yacs.config import CfgNode
+
 from paddlespeech.s2t.exps.u2_st.model import U2STTester as Tester
 from paddlespeech.s2t.training.cli import default_argument_parser
 from paddlespeech.s2t.utils.utility import print_arguments
diff --git a/paddlespeech/s2t/exps/u2_st/model.py b/paddlespeech/s2t/exps/u2_st/model.py
index ca2c2c1d..b03ca38b 100644
--- a/paddlespeech/s2t/exps/u2_st/model.py
+++ b/paddlespeech/s2t/exps/u2_st/model.py
@@ -18,13 +18,11 @@ import time
 from collections import defaultdict
 from collections import OrderedDict
 from contextlib import nullcontext
-from typing import Optional
 
 import jsonlines
 import numpy as np
 import paddle
 from paddle import distributed as dist
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.featurizer import TextFeaturizer
 from paddlespeech.s2t.io.dataloader import BatchDataLoader
@@ -208,8 +206,7 @@ class U2STTrainer(Trainer):
                                 k.split(',')) == 2 else ""
                             msg += ","
                         msg = msg[:-1]  # remove the last ","
-                        if (batch_index + 1
-                            ) % self.config.log_interval == 0:
+                        if (batch_index + 1) % self.config.log_interval == 0:
                             logger.info(msg)
                 except Exception as e:
                     logger.error(e)
@@ -260,7 +257,8 @@ class U2STTrainer(Trainer):
                 batch_frames_in=0,
                 batch_frames_out=0,
                 batch_frames_inout=0,
-                preprocess_conf=config.preprocess_config,  # aug will be off when train_mode=False
+                preprocess_conf=config.
+                preprocess_config,  # aug will be off when train_mode=False
                 n_iter_processes=config.num_workers,
                 subsampling_factor=1,
                 load_aux_output=load_transcript,
@@ -281,7 +279,8 @@ class U2STTrainer(Trainer):
                 batch_frames_in=0,
                 batch_frames_out=0,
                 batch_frames_inout=0,
-                preprocess_conf=config.preprocess_config,  # aug will be off when train_mode=False
+                preprocess_conf=config.
+                preprocess_config,  # aug will be off when train_mode=False
                 n_iter_processes=config.num_workers,
                 subsampling_factor=1,
                 load_aux_output=load_transcript,
@@ -290,7 +289,8 @@ class U2STTrainer(Trainer):
             logger.info("Setup train/valid Dataloader!")
         else:
             # test dataset, return raw text
-            decode_batch_size = config.get('decode',dict()).get('decode_batch_size', 1)
+            decode_batch_size = config.get('decode', dict()).get(
+                'decode_batch_size', 1)
             self.test_loader = BatchDataLoader(
                 json_file=config.test_manifest,
                 train_mode=False,
@@ -305,7 +305,8 @@ class U2STTrainer(Trainer):
                 batch_frames_in=0,
                 batch_frames_out=0,
                 batch_frames_inout=0,
-                preprocess_conf=config.preprocess_config,  # aug will be off when train_mode=False
+                preprocess_conf=config.
+                preprocess_config,  # aug will be off when train_mode=False
                 n_iter_processes=config.num_workers,
                 subsampling_factor=1,
                 num_encs=1,
diff --git a/paddlespeech/s2t/io/collator.py b/paddlespeech/s2t/io/collator.py
index 3a14b2d5..b99fc80c 100644
--- a/paddlespeech/s2t/io/collator.py
+++ b/paddlespeech/s2t/io/collator.py
@@ -12,10 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 import io
-from typing import Optional
 
 import numpy as np
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.augmentor.augmentation import AugmentationPipeline
 from paddlespeech.s2t.frontend.featurizer.speech_featurizer import SpeechFeaturizer
diff --git a/paddlespeech/s2t/io/dataset.py b/paddlespeech/s2t/io/dataset.py
index 9149fb27..0e94f047 100644
--- a/paddlespeech/s2t/io/dataset.py
+++ b/paddlespeech/s2t/io/dataset.py
@@ -13,11 +13,8 @@
 # limitations under the License.
 # Modified from espnet(https://github.com/espnet/espnet)
 # Modified from wenet(https://github.com/wenet-e2e/wenet)
-from typing import Optional
-
 import jsonlines
 from paddle.io import Dataset
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.utility import read_manifest
 from paddlespeech.s2t.utils.log import Log
diff --git a/paddlespeech/s2t/models/ds2/deepspeech2.py b/paddlespeech/s2t/models/ds2/deepspeech2.py
index ddc3612d..a478ba82 100644
--- a/paddlespeech/s2t/models/ds2/deepspeech2.py
+++ b/paddlespeech/s2t/models/ds2/deepspeech2.py
@@ -12,11 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Deepspeech2 ASR Model"""
-from typing import Optional
-
 import paddle
 from paddle import nn
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.models.ds2.conv import ConvStack
 from paddlespeech.s2t.models.ds2.rnn import RNNStack
@@ -119,6 +116,7 @@ class DeepSpeech2Model(nn.Layer):
              before softmax) and a ctc cost layer.
     :rtype: tuple of LayerOutput
     """
+
     def __init__(self,
                  feat_size,
                  dict_size,
diff --git a/paddlespeech/s2t/models/ds2_online/deepspeech2.py b/paddlespeech/s2t/models/ds2_online/deepspeech2.py
index aae77f74..7d463755 100644
--- a/paddlespeech/s2t/models/ds2_online/deepspeech2.py
+++ b/paddlespeech/s2t/models/ds2_online/deepspeech2.py
@@ -12,12 +12,9 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 """Deepspeech2 ASR Online Model"""
-from typing import Optional
-
 import paddle
 import paddle.nn.functional as F
 from paddle import nn
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.models.ds2_online.conv import Conv2dSubsampling4Online
 from paddlespeech.s2t.modules.ctc import CTCDecoder
@@ -243,6 +240,7 @@ class DeepSpeech2ModelOnline(nn.Layer):
              before softmax) and a ctc cost layer.
     :rtype: tuple of LayerOutput
     """
+
     def __init__(
             self,
             feat_size,
diff --git a/paddlespeech/s2t/models/u2/u2.py b/paddlespeech/s2t/models/u2/u2.py
index 26e81acf..d920a200 100644
--- a/paddlespeech/s2t/models/u2/u2.py
+++ b/paddlespeech/s2t/models/u2/u2.py
@@ -26,7 +26,6 @@ from typing import Tuple
 import paddle
 from paddle import jit
 from paddle import nn
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.decoders.scorers.ctc import CTCPrefixScorer
 from paddlespeech.s2t.frontend.utility import IGNORE_ID
@@ -59,6 +58,7 @@ logger = Log(__name__).getlog()
 
 class U2BaseModel(ASRInterface, nn.Layer):
     """CTC-Attention hybrid Encoder-Decoder model"""
+
     def __init__(self,
                  vocab_size: int,
                  encoder: TransformerEncoder,
diff --git a/paddlespeech/s2t/models/u2_st/u2_st.py b/paddlespeech/s2t/models/u2_st/u2_st.py
index 1c5596ba..2aa0b347 100644
--- a/paddlespeech/s2t/models/u2_st/u2_st.py
+++ b/paddlespeech/s2t/models/u2_st/u2_st.py
@@ -24,7 +24,6 @@ from typing import Tuple
 import paddle
 from paddle import jit
 from paddle import nn
-from yacs.config import CfgNode
 
 from paddlespeech.s2t.frontend.utility import IGNORE_ID
 from paddlespeech.s2t.frontend.utility import load_cmvn
@@ -51,6 +50,7 @@ logger = Log(__name__).getlog()
 
 class U2STBaseModel(nn.Layer):
     """CTC-Attention hybrid Encoder-Decoder model"""
+
     def __init__(self,
                  vocab_size: int,
                  encoder: TransformerEncoder,