apply isort & flake8

diff --git a/mlnode/iotdb/mlnode/algorithm/factory.py b/mlnode/iotdb/mlnode/algorithm/factory.py
index c877113..ed39e4e 100644
--- a/mlnode/iotdb/mlnode/algorithm/factory.py
+++ b/mlnode/iotdb/mlnode/algorithm/factory.py

@@ -15,10 +15,10 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-import torch.nn as nn
-
 from typing import Dict, Tuple
 
+import torch.nn as nn
+
 from iotdb.mlnode.algorithm.enums import ForecastModelType, ForecastTaskType
 from iotdb.mlnode.algorithm.models.forecast.dlinear import (dlinear,
                                                             dlinear_individual)

diff --git a/mlnode/iotdb/mlnode/algorithm/metric.py b/mlnode/iotdb/mlnode/algorithm/metric.py
index 562ffe0..1835b77 100644
--- a/mlnode/iotdb/mlnode/algorithm/metric.py
+++ b/mlnode/iotdb/mlnode/algorithm/metric.py

@@ -17,6 +17,7 @@
 #
 from abc import abstractmethod
 from typing import Dict
+
 import numpy as np
 
 all_metrics = ['RSE', 'CORR', 'MAE', 'MSE', 'RMSE', 'MAPE', 'MSPE']

diff --git a/mlnode/iotdb/mlnode/client.py b/mlnode/iotdb/mlnode/client.py
index d39156e..3157006 100644
--- a/mlnode/iotdb/mlnode/client.py
+++ b/mlnode/iotdb/mlnode/client.py

@@ -16,14 +16,14 @@
 # under the License.
 #
 import time
-from typing import List, Dict
+from typing import Dict, List
 
 import pandas as pd
-from iotdb.mlnode import serde
 from thrift.protocol import TBinaryProtocol, TCompactProtocol
 from thrift.Thrift import TException
 from thrift.transport import TSocket, TTransport
 
+from iotdb.mlnode import serde
 from iotdb.mlnode.config import descriptor
 from iotdb.mlnode.constant import TSStatusCode
 from iotdb.mlnode.log import logger
@@ -34,7 +34,6 @@
                                             TUpdateModelStateReq)
 from iotdb.thrift.datanode import IMLNodeInternalRPCService
 from iotdb.thrift.datanode.ttypes import (TFetchTimeseriesReq,
-                                          TFetchTimeseriesResp,
                                           TRecordModelMetricsReq)
 from iotdb.thrift.mlnode import IMLNodeRPCService
 from iotdb.thrift.mlnode.ttypes import TCreateTrainingTaskReq, TDeleteModelReq

diff --git a/mlnode/iotdb/mlnode/data_access/factory.py b/mlnode/iotdb/mlnode/data_access/factory.py
index 4c62ae3..3c4c1a4 100644
--- a/mlnode/iotdb/mlnode/data_access/factory.py
+++ b/mlnode/iotdb/mlnode/data_access/factory.py

@@ -15,8 +15,10 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-from torch.utils.data import Dataset
 from typing import Dict, Tuple
+
+from torch.utils.data import Dataset
+
 from iotdb.mlnode.data_access.enums import DatasetType, DataSourceType
 from iotdb.mlnode.data_access.offline.dataset import (TimeSeriesDataset,
                                                       WindowDataset)

diff --git a/mlnode/iotdb/mlnode/data_access/offline/dataset.py b/mlnode/iotdb/mlnode/data_access/offline/dataset.py
index 3c42e92..a1b11cc 100644
--- a/mlnode/iotdb/mlnode/data_access/offline/dataset.py
+++ b/mlnode/iotdb/mlnode/data_access/offline/dataset.py

@@ -15,10 +15,11 @@
 # specific language governing permissions and limitations
 # under the License.
 #
-import numpy as np
-
-from torch.utils.data import Dataset
 from typing import Tuple
+
+import numpy as np
+from torch.utils.data import Dataset
+
 from iotdb.mlnode.data_access.offline.source import DataSource
 from iotdb.mlnode.data_access.utils.timefeatures import time_features
 

diff --git a/mlnode/iotdb/mlnode/data_access/offline/source.py b/mlnode/iotdb/mlnode/data_access/offline/source.py
index c1811bb..e204409 100644
--- a/mlnode/iotdb/mlnode/data_access/offline/source.py
+++ b/mlnode/iotdb/mlnode/data_access/offline/source.py

@@ -18,7 +18,6 @@
 import numpy as np
 import pandas as pd
 
-from iotdb.mlnode import serde
 from iotdb.mlnode.client import client_manager
 
 

diff --git a/mlnode/iotdb/mlnode/parser.py b/mlnode/iotdb/mlnode/parser.py
index 8788885..294f6af 100644
--- a/mlnode/iotdb/mlnode/parser.py
+++ b/mlnode/iotdb/mlnode/parser.py

@@ -17,10 +17,9 @@
 #
 
 
-import re
 import argparse
-
-from typing import List, Dict, Tuple
+import re
+from typing import Dict, List, Tuple
 
 from iotdb.mlnode.algorithm.enums import ForecastTaskType
 from iotdb.mlnode.data_access.enums import DatasetType, DataSourceType

diff --git a/mlnode/iotdb/mlnode/storage.py b/mlnode/iotdb/mlnode/storage.py
index 78ecb35..84d7dfd 100644
--- a/mlnode/iotdb/mlnode/storage.py
+++ b/mlnode/iotdb/mlnode/storage.py

@@ -19,11 +19,12 @@
 import json
 import os
 import shutil
+from typing import Dict, Tuple
 
 import torch
 import torch.nn as nn
 from pylru import lrucache
-from typing import Dict, Tuple
+
 from iotdb.mlnode.config import descriptor
 from iotdb.mlnode.exception import ModelNotExistError
 from iotdb.mlnode.log import logger