diff --git a/tests/test-umockdev.py b/tests/test-umockdev.py
index 5b8c1e2..a7e5b71 100644
--- a/tests/test-umockdev.py
+++ b/tests/test-umockdev.py
@@ -18,11 +18,11 @@
 # You should have received a copy of the GNU Lesser General Public License
 # along with this program; If not, see <http://www.gnu.org/licenses/>.
 
-import sys
-import os.path
-import unittest
 import fcntl
+import os.path
 import struct
+import sys
+import unittest
 import warnings
 
 try:
@@ -41,6 +41,7 @@
     warnings.filterwarnings('ignore', category=DeprecationWarning)
     from gi.repository import UMockdev
 
+
 class Testbed(unittest.TestCase):
     def setUp(self):
         self.testbed = UMockdev.Testbed.new()
@@ -180,7 +181,7 @@ def on_uevent(client, action, device, counters):
         self.assertEqual(counter, [0, 0, 1, syspath, '0815', '1'])
 
     def test_add_from_string(self):
-        self.assertTrue(self.testbed.add_from_string ('''P: /devices/dev1
+        self.assertTrue(self.testbed.add_from_string('''P: /devices/dev1
 E: SIMPLE_PROP=1
 E: SUBSYSTEM=pci
 H: binary_attr=41FF0005FF00
@@ -193,13 +194,13 @@ def test_add_from_string(self):
         devices = enum.execute()
         self.assertEqual([d.get_sysfs_path() for d in devices], ['/sys/devices/dev1'])
 
-        device = client.query_by_sysfs_path ('/sys/devices/dev1')
-        self.assertEqual (device.get_subsystem(), 'pci')
-        #self.assertEqual (device.get_parent(), None)
-        self.assertEqual (device.get_sysfs_attr('simple_attr'), '1')
-        self.assertEqual (device.get_sysfs_attr('multiline_attr'),
-                          'a\\b\nc\\d\nlast')
-        self.assertEqual (device.get_property('SIMPLE_PROP'), '1')
+        device = client.query_by_sysfs_path('/sys/devices/dev1')
+        self.assertEqual(device.get_subsystem(), 'pci')
+        # self.assertEqual(device.get_parent(), None)
+        self.assertEqual(device.get_sysfs_attr('simple_attr'), '1')
+        self.assertEqual(device.get_sysfs_attr('multiline_attr'),
+                         'a\\b\nc\\d\nlast')
+        self.assertEqual(device.get_property('SIMPLE_PROP'), '1')
         with open(os.path.join(self.testbed.get_root_dir(),
                                '/sys/devices/dev1/binary_attr'), 'rb') as f:
             self.assertEqual(f.read(), b'\x41\xFF\x00\x05\xFF\x00')
@@ -213,12 +214,12 @@ def test_add_from_string_errors(self):
             assertRaisesRegex = self.assertRaisesRegexp
 
         # does not start with P:
-        with assertRaisesRegex(GLib.GError, 'must start with.*P:') as cm:
-            self.testbed.add_from_string ('E: SIMPLE_PROP=1\n')
+        with assertRaisesRegex(GLib.GError, 'must start with.*P:'):
+            self.testbed.add_from_string('E: SIMPLE_PROP=1\n')
 
         # no value
-        with assertRaisesRegex(GLib.GError, 'malformed attribute') as cm:
-            self.testbed.add_from_string ('P: /devices/dev1\nE: SIMPLE_PROP\n')
+        with assertRaisesRegex(GLib.GError, 'malformed attribute'):
+            self.testbed.add_from_string('P: /devices/dev1\nE: SIMPLE_PROP\n')
 
     def test_custom_ioctl(self):
         handler = UMockdev.IoctlBase()
@@ -240,7 +241,7 @@ def handle_ioctl(handler, client):
 
         handler.connect("handle-ioctl", handle_ioctl)
 
-        self.testbed.add_from_string ('P: /devices/test\nN: test\nE: SUBSYSTEM=test')
+        self.testbed.add_from_string('P: /devices/test\nN: test\nE: SUBSYSTEM=test')
         self.testbed.attach_ioctl('/dev/test', handler)
 
         fd = os.open('/dev/test', os.O_RDONLY)
@@ -253,4 +254,5 @@ def handle_ioctl(handler, client):
         self.testbed.detach_ioctl('/dev/test')
         self.testbed.attach_ioctl('/dev/test', handler)
 
+
 unittest.main(testRunner=unittest.TextTestRunner(stream=sys.stdout, verbosity=2))