diff --git a/server/visualdl/lib.py b/server/visualdl/lib.py
index e22cd07a7e7f7066f3a43bd65109170bec96a878..115177b24dd703dd5c68d30495c9728268a2cdb0 100644
--- a/server/visualdl/lib.py
+++ b/server/visualdl/lib.py
@@ -1,10 +1,12 @@
-import numpy as np
-import re
-import storage
-from PIL import Image
-from tempfile import NamedTemporaryFile
 import pprint
+import re
 import urllib
+from tempfile import NamedTemporaryFile
+
+import numpy as np
+from PIL import Image
+
+import storage
 
 
 def get_scalar_tags(storage, mode):
diff --git a/server/visualdl/storage_mock.py b/server/visualdl/storage_mock.py
index 7ccf4f92d64cccf7de39295fd3fbb3965fbd2bfe..1192f92e4a9eddaeca37651751087b2aa139676b 100644
--- a/server/visualdl/storage_mock.py
+++ b/server/visualdl/storage_mock.py
@@ -1,8 +1,10 @@
-import storage
-import numpy as np
-import unittest
 import random
 import time
+import unittest
+
+import numpy as np
+
+import storage
 
 dir = "./tmp/mock"
 writer = storage.StorageWriter(dir, sync_cycle=20)
diff --git a/server/visualdl/visual_dl.py b/server/visualdl/visual_dl.py
index 24228edcf5e5680ca253af0f587d8592e1f948b3..6620bef8222aa208113289be80bb5929f6c86886 100644
--- a/server/visualdl/visual_dl.py
+++ b/server/visualdl/visual_dl.py
@@ -4,16 +4,14 @@ import re
 import sys
 from optparse import OptionParser
 
-from flask import Flask, redirect
-from flask import request
-from flask import send_from_directory, send_file
-from flask import Response
+from flask import (Flask, Response, redirect, request, send_file,
+                   send_from_directory)
 
-from visualdl.log import logger
+import lib
+import storage
 import visualdl.mock.data as mock_data
 import visualdl.mock.tags as mock_tags
-import storage
-import lib
+from visualdl.log import logger
 
 app = Flask(__name__, static_url_path="")
 
diff --git a/visualdl/python/test_storage.py b/visualdl/python/test_storage.py
index 9a49a1103e594758ed1c5f6081313aa1748c3e5b..05ae2f24c9631a654272a79a3b7ec3b83cfb2e0d 100644
--- a/visualdl/python/test_storage.py
+++ b/visualdl/python/test_storage.py
@@ -1,8 +1,10 @@
-import storage
-import numpy as np
-import unittest
 import random
 import time
+import unittest
+
+import numpy as np
+
+import storage
 
 
 class StorageTest(unittest.TestCase):