diff --git a/pyexcel_xls/__init__.py b/pyexcel_xls/__init__.py
index 5c513bb..b890347 100644
--- a/pyexcel_xls/__init__.py
+++ b/pyexcel_xls/__init__.py
@@ -7,6 +7,7 @@
     :copyright: (c) 2016-2021 by Onni Software Ltd
     :license: New BSD License
 """
+
 import xlrd
 
 # flake8: noqa
diff --git a/pyexcel_xls/xlsr.py b/pyexcel_xls/xlsr.py
index c9f15e8..88fe989 100644
--- a/pyexcel_xls/xlsr.py
+++ b/pyexcel_xls/xlsr.py
@@ -7,6 +7,7 @@
     :copyright: (c) 2016-2021 by Onni Software Ltd
     :license: New BSD License
 """
+
 import datetime
 
 import xlrd
diff --git a/pyexcel_xls/xlsw.py b/pyexcel_xls/xlsw.py
index f70ec64..bbd2e67 100644
--- a/pyexcel_xls/xlsw.py
+++ b/pyexcel_xls/xlsw.py
@@ -7,6 +7,7 @@
     :copyright: (c) 2016-2021 by Onni Software Ltd
     :license: New BSD License
 """
+
 import datetime
 
 import xlrd
diff --git a/tests/base.py b/tests/base.py
index aa7c817..1a8ef6b 100644
--- a/tests/base.py
+++ b/tests/base.py
@@ -81,7 +81,7 @@ def test_reading_through_sheets(self):
         expected = [[4, 4, 4, 4], [5, 5, 5, 5], [6, 6, 6, 6]]
         assert data == expected
         data = list(b["Sheet3"].rows())
-        expected = [[u"X", u"Y", u"Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]]
+        expected = [["X", "Y", "Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]]
         assert data == expected
         sheet3 = b["Sheet3"]
         sheet3.name_columns_by_row(0)
diff --git a/tests/test_bug_fixes.py b/tests/test_bug_fixes.py
index a519940..89c2464 100644
--- a/tests/test_bug_fixes.py
+++ b/tests/test_bug_fixes.py
@@ -8,14 +8,13 @@
 import datetime
 from unittest.mock import MagicMock, patch
 
+import pytest
 import pyexcel as pe
 from _compact import OrderedDict
 from pyexcel_xls import XLRD_VERSION_2_OR_ABOVE, save_data
 from pyexcel_xls.xlsr import xldate_to_python_date
 from pyexcel_xls.xlsw import XLSWriter as Writer
 
-import pytest
-
 IN_TRAVIS = "TRAVIS" in os.environ
 
 
diff --git a/tests/test_multiple_sheets.py b/tests/test_multiple_sheets.py
index 6708815..42b523d 100644
--- a/tests/test_multiple_sheets.py
+++ b/tests/test_multiple_sheets.py
@@ -1,11 +1,10 @@
 import os
 import sys
 
+import pytest
 import pyexcel
 from base import PyexcelMultipleSheetBase
 
-import pytest
-
 if sys.version_info[0] == 2 and sys.version_info[1] < 7:
     from ordereddict import OrderedDict
 else:
@@ -231,6 +230,6 @@ def _produce_ordered_dict():
     data_dict.update({"Sheet1": [[1, 1, 1, 1], [2, 2, 2, 2], [3, 3, 3, 3]]})
     data_dict.update({"Sheet2": [[4, 4, 4, 4], [5, 5, 5, 5], [6, 6, 6, 6]]})
     data_dict.update(
-        {"Sheet3": [[u"X", u"Y", u"Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]]}
+        {"Sheet3": [["X", "Y", "Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]]}
     )
     return data_dict
diff --git a/tests/test_writer.py b/tests/test_writer.py
index 41b7344..79759ce 100644
--- a/tests/test_writer.py
+++ b/tests/test_writer.py
@@ -10,7 +10,7 @@ def test_write_book(self):
         self.content = {
             "Sheet1": [[1, 1, 1, 1], [2, 2, 2, 2], [3, 3, 3, 3]],
             "Sheet2": [[4, 4, 4, 4], [5, 5, 5, 5], [6, 6, 6, 6]],
-            "Sheet3": [[u"X", u"Y", u"Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]],
+            "Sheet3": [["X", "Y", "Z"], [1, 4, 7], [2, 5, 8], [3, 6, 9]],
         }
         self.testfile = "writer.xls"
         writer = Writer(self.testfile, "xls")