diff --git a/slycot/tests/test_ab01.py b/slycot/tests/test_ab01.py
index ec544b13..01c1242b 100644
--- a/slycot/tests/test_ab01.py
+++ b/slycot/tests/test_ab01.py
@@ -6,7 +6,6 @@
 
 from numpy import array
 from numpy.testing import assert_allclose, assert_equal
-
 from scipy.linalg.lapack import dorgqr
 
 from slycot.analysis import ab01nd
diff --git a/slycot/tests/test_ab04md.py b/slycot/tests/test_ab04md.py
index 076c4a6c..bafee439 100644
--- a/slycot/tests/test_ab04md.py
+++ b/slycot/tests/test_ab04md.py
@@ -1,8 +1,8 @@
-from slycot import analysis
 import numpy as np
-
 from numpy.testing import assert_allclose
 
+from slycot import analysis
+
 
 class Test_ab04md:
     """Test ab04md.
diff --git a/slycot/tests/test_ab08n.py b/slycot/tests/test_ab08n.py
index 130ae95d..c777fc07 100644
--- a/slycot/tests/test_ab08n.py
+++ b/slycot/tests/test_ab08n.py
@@ -1,11 +1,11 @@
 # ===================================================
 # ab08n* tests
 
-from slycot import analysis
 import numpy as np
-
+from numpy.testing import assert_allclose, assert_equal
 from scipy.linalg import eig
-from numpy.testing import assert_equal, assert_allclose
+
+from slycot import analysis
 
 
 class Test_ab08nX:
diff --git a/slycot/tests/test_ab13bd.py b/slycot/tests/test_ab13bd.py
index db4a2bd7..dd2a735a 100644
--- a/slycot/tests/test_ab13bd.py
+++ b/slycot/tests/test_ab13bd.py
@@ -1,12 +1,12 @@
 # ===================================================
 # ab08n* tests
 
-from slycot import analysis
 import numpy as np
+from numpy.testing import assert_allclose, assert_array_equal, assert_equal
+from scipy import linalg, signal
+
+from slycot import analysis
 
-from scipy import linalg
-from scipy import signal
-from numpy.testing import assert_equal, assert_allclose, assert_array_equal
 
 class Test_ab13bd:
     """ Test regular pencil construction ab08nX with input parameters
diff --git a/slycot/tests/test_ab13md.py b/slycot/tests/test_ab13md.py
index df69a6b3..5a30f5ba 100644
--- a/slycot/tests/test_ab13md.py
+++ b/slycot/tests/test_ab13md.py
@@ -1,7 +1,6 @@
 import numpy as np
-from numpy.testing import assert_allclose, assert_array_less
-
 import pytest
+from numpy.testing import assert_allclose, assert_array_less
 
 from slycot import ab13md
 
diff --git a/slycot/tests/test_ag08bd.py b/slycot/tests/test_ag08bd.py
index e849cef4..97aa2b41 100644
--- a/slycot/tests/test_ag08bd.py
+++ b/slycot/tests/test_ag08bd.py
@@ -1,10 +1,10 @@
 """Verify ag08bd with input parameters according to example in documentation."""
 
-from slycot import analysis
 import numpy as np
-
 from numpy.testing import assert_almost_equal, assert_equal
 
+from slycot import analysis
+
 # test1 input parameters
 
 test1_l = 9
diff --git a/slycot/tests/test_analysis.py b/slycot/tests/test_analysis.py
index 701eab4a..0b899580 100644
--- a/slycot/tests/test_analysis.py
+++ b/slycot/tests/test_analysis.py
@@ -3,10 +3,12 @@
 # repagh <rene.vanpaassen@gmail.com, May 2020
 
 import pytest
-from .test_exceptions import assert_docstring_parse
+
 from slycot import analysis
 from slycot.exceptions import SlycotArithmeticError, SlycotResultWarning
 
+from .test_exceptions import assert_docstring_parse
+
 
 @pytest.mark.parametrize(
     'fun,              exception_class,       erange,         checkvars',
diff --git a/slycot/tests/test_examples.py b/slycot/tests/test_examples.py
index 1197e14a..c7d04943 100644
--- a/slycot/tests/test_examples.py
+++ b/slycot/tests/test_examples.py
@@ -6,6 +6,7 @@
 """
 
 from inspect import getmembers, isfunction
+
 import pytest
 
 from slycot import examples
diff --git a/slycot/tests/test_exceptions.py b/slycot/tests/test_exceptions.py
index c0ce66a3..b370c34e 100644
--- a/slycot/tests/test_exceptions.py
+++ b/slycot/tests/test_exceptions.py
@@ -24,9 +24,9 @@
 
 import pytest
 
-from slycot.exceptions import raise_if_slycot_error, \
-                              SlycotError, SlycotWarning, SlycotParameterError
 from slycot import _wrapper
+from slycot.exceptions import (SlycotError, SlycotParameterError,
+                               SlycotWarning, raise_if_slycot_error)
 
 
 def assert_docstring_parse(docstring, exception_class, erange, checkvars={}):
diff --git a/slycot/tests/test_mc.py b/slycot/tests/test_mc.py
index b27c0481..e1650068 100644
--- a/slycot/tests/test_mc.py
+++ b/slycot/tests/test_mc.py
@@ -2,9 +2,10 @@
 # test_mc.py - test suite for polynomial and rational function manipulation
 # bnavigator <code@bnavigator.de>, Aug 2019
 
-import pytest
 import re
 
+import pytest
+
 from slycot import mc01td
 from slycot.exceptions import SlycotResultWarning
 
diff --git a/slycot/tests/test_sb.py b/slycot/tests/test_sb.py
index 00e406db..e6f97a07 100644
--- a/slycot/tests/test_sb.py
+++ b/slycot/tests/test_sb.py
@@ -1,14 +1,14 @@
 # ===================================================
 # sb* synthesis tests
 
-from slycot import synthesis
-from slycot.exceptions import raise_if_slycot_error, \
-                              SlycotParameterError, SlycotArithmeticError, \
-                              SlycotResultWarning
-
+import pytest
 from numpy import array, eye, zeros
 from numpy.testing import assert_allclose, assert_raises
-import pytest
+
+from slycot import synthesis
+from slycot.exceptions import (SlycotArithmeticError, SlycotParameterError,
+                               SlycotResultWarning, raise_if_slycot_error)
+
 from .test_exceptions import assert_docstring_parse
 
 
diff --git a/slycot/tests/test_sg02ad.py b/slycot/tests/test_sg02ad.py
index d640b159..1576a8ec 100644
--- a/slycot/tests/test_sg02ad.py
+++ b/slycot/tests/test_sg02ad.py
@@ -2,11 +2,12 @@
 # test_sg02ad.py - test suite for ricatti equation solving
 # RvP, 19 Jun 2017
 
-from slycot import synthesis
 import numpy as np
-
 from numpy.testing import assert_almost_equal
 
+from slycot import synthesis
+
+
 def test_sg02ad_case1():
     n = 3
     m = 1
diff --git a/slycot/tests/test_sg03ad.py b/slycot/tests/test_sg03ad.py
index 1352ebb8..a5976e0d 100644
--- a/slycot/tests/test_sg03ad.py
+++ b/slycot/tests/test_sg03ad.py
@@ -2,11 +2,11 @@
 # test_sg03ad.py - test suite for stability margin commands
 # RvP, 15 Jun 2017
 
-from slycot import synthesis
 import numpy as np
-
 from numpy.testing import assert_almost_equal
 
+from slycot import synthesis
+
 # test cases from
 # Penzl T., Numerical Solution of Generalized Lyapunov Equations
 # http://www.qucosa.de/fileadmin/data/qucosa/documents/4168/data/b002.pdf
diff --git a/slycot/tests/test_tb05ad.py b/slycot/tests/test_tb05ad.py
index b5a1d3e3..900a49a2 100644
--- a/slycot/tests/test_tb05ad.py
+++ b/slycot/tests/test_tb05ad.py
@@ -3,10 +3,10 @@
 
 import sys
 
-import pytest
 import numpy as np
-from scipy.linalg import matrix_balance, eig
+import pytest
 from numpy.testing import assert_almost_equal
+from scipy.linalg import eig, matrix_balance
 
 from slycot import transform
 from slycot.exceptions import SlycotArithmeticError, SlycotParameterError
diff --git a/slycot/tests/test_tg01ad.py b/slycot/tests/test_tg01ad.py
index db9479aa..864d41be 100644
--- a/slycot/tests/test_tg01ad.py
+++ b/slycot/tests/test_tg01ad.py
@@ -1,10 +1,10 @@
 # ===================================================
 # tg01ad tests
 
-from slycot import transform
 import numpy as np
+from numpy.testing import assert_almost_equal, assert_equal, assert_raises
 
-from numpy.testing import assert_raises, assert_almost_equal, assert_equal
+from slycot import transform
 
 # test1 input parameters
 
diff --git a/slycot/tests/test_tg01fd.py b/slycot/tests/test_tg01fd.py
index 70ebef19..902d1ef2 100644
--- a/slycot/tests/test_tg01fd.py
+++ b/slycot/tests/test_tg01fd.py
@@ -1,10 +1,10 @@
 # ===================================================
 # tg01fd tests
 
-from slycot import transform
 import numpy as np
+from numpy.testing import assert_almost_equal, assert_equal, assert_raises
 
-from numpy.testing import assert_raises, assert_almost_equal, assert_equal
+from slycot import transform
 
 # test1 input parameters
 test1_l = 4
diff --git a/slycot/tests/test_transform.py b/slycot/tests/test_transform.py
index fa22c514..928ac5d4 100644
--- a/slycot/tests/test_transform.py
+++ b/slycot/tests/test_transform.py
@@ -3,10 +3,12 @@
 # repagh <rene.vanpaassen@gmail.com, May 2020
 
 import pytest
-from .test_exceptions import assert_docstring_parse
+
 from slycot import transform as tf
 from slycot.exceptions import SlycotArithmeticError
 
+from .test_exceptions import assert_docstring_parse
+
 
 @pytest.mark.parametrize(
     'fun,        exception_class,       erange,         checkvars',