Adopt Black and isort (SC-700) (#1157)

Applied Black and isort, fixed any linting issues, updated tox.ini
and CI.

1 files changed, 160 insertions, 151 deletions

diff --git a/tests/unittests/sources/test_altcloud.py b/tests/unittests/sources/test_altcloud.py
index 7384c104..44dfafd9 100644
--- a/tests/unittests/sources/test_altcloud.py
+++ b/tests/unittests/sources/test_altcloud.py
@@ -6,54 +6,47 @@
 #
 # This file is part of cloud-init. See LICENSE file for license information.
 
-'''
+"""
 This test file exercises the code in sources DataSourceAltCloud.py
-'''
+"""
 
 import os
 import shutil
 import tempfile
 
-from cloudinit import dmi
-from cloudinit import helpers
-from cloudinit import subp
-from cloudinit import util
-
-from tests.unittests.helpers import CiTestCase, mock
-
 import cloudinit.sources.DataSourceAltCloud as dsac
+from cloudinit import dmi, helpers, subp, util
+from tests.unittests.helpers import CiTestCase, mock
 
-OS_UNAME_ORIG = getattr(os, 'uname')
+OS_UNAME_ORIG = getattr(os, "uname")
 
 
 def _write_user_data_files(mount_dir, value):
-    '''
+    """
     Populate the deltacloud_user_data_file the user_data_file
     which would be populated with user data.
-    '''
-    deltacloud_user_data_file = mount_dir + '/deltacloud-user-data.txt'
-    user_data_file = mount_dir + '/user-data.txt'
+    """
+    deltacloud_user_data_file = mount_dir + "/deltacloud-user-data.txt"
+    user_data_file = mount_dir + "/user-data.txt"
 
-    udfile = open(deltacloud_user_data_file, 'w')
+    udfile = open(deltacloud_user_data_file, "w")
     udfile.write(value)
     udfile.close()
     os.chmod(deltacloud_user_data_file, 0o664)
 
-    udfile = open(user_data_file, 'w')
+    udfile = open(user_data_file, "w")
     udfile.write(value)
     udfile.close()
     os.chmod(user_data_file, 0o664)
 
 
-def _remove_user_data_files(mount_dir,
-                            dc_file=True,
-                            non_dc_file=True):
-    '''
+def _remove_user_data_files(mount_dir, dc_file=True, non_dc_file=True):
+    """
     Remove the test files: deltacloud_user_data_file and
     user_data_file
-    '''
-    deltacloud_user_data_file = mount_dir + '/deltacloud-user-data.txt'
-    user_data_file = mount_dir + '/user-data.txt'
+    """
+    deltacloud_user_data_file = mount_dir + "/deltacloud-user-data.txt"
+    user_data_file = mount_dir + "/user-data.txt"
 
     # Ignore any failures removeing files that are already gone.
     if dc_file:
@@ -70,9 +63,10 @@ def _remove_user_data_files(mount_dir,
 
 
 def _dmi_data(expected):
-    '''
+    """
     Spoof the data received over DMI
-    '''
+    """
+
     def _data(key):
         return expected
 
@@ -80,19 +74,19 @@ def _dmi_data(expected):
 
 
 class TestGetCloudType(CiTestCase):
-    '''Test to exercise method: DataSourceAltCloud.get_cloud_type()'''
+    """Test to exercise method: DataSourceAltCloud.get_cloud_type()"""
 
     with_logs = True
 
     def setUp(self):
-        '''Set up.'''
+        """Set up."""
         super(TestGetCloudType, self).setUp()
         self.tmp = self.tmp_dir()
-        self.paths = helpers.Paths({'cloud_dir': self.tmp})
+        self.paths = helpers.Paths({"cloud_dir": self.tmp})
         self.dmi_data = dmi.read_dmi_data
         # We have a different code path for arm to deal with LP1243287
         # We have to switch arch to x86_64 to avoid test failure
-        force_arch('x86_64')
+        force_arch("x86_64")
 
     def tearDown(self):
         # Reset
@@ -101,216 +95,226 @@ class TestGetCloudType(CiTestCase):
 
     def test_cloud_info_file_ioerror(self):
         """Return UNKNOWN when /etc/sysconfig/cloud-info exists but errors."""
-        self.assertEqual('/etc/sysconfig/cloud-info', dsac.CLOUD_INFO_FILE)
+        self.assertEqual("/etc/sysconfig/cloud-info", dsac.CLOUD_INFO_FILE)
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         # Attempting to read the directory generates IOError
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.tmp):
-            self.assertEqual('UNKNOWN', dsrc.get_cloud_type())
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.tmp):
+            self.assertEqual("UNKNOWN", dsrc.get_cloud_type())
         self.assertIn(
-            "[Errno 21] Is a directory: '%s'" % self.tmp,
-            self.logs.getvalue())
+            "[Errno 21] Is a directory: '%s'" % self.tmp, self.logs.getvalue()
+        )
 
     def test_cloud_info_file(self):
         """Return uppercase stripped content from /etc/sysconfig/cloud-info."""
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        cloud_info = self.tmp_path('cloud-info', dir=self.tmp)
-        util.write_file(cloud_info, ' OverRiDdeN CloudType ')
+        cloud_info = self.tmp_path("cloud-info", dir=self.tmp)
+        util.write_file(cloud_info, " OverRiDdeN CloudType ")
         # Attempting to read the directory generates IOError
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', cloud_info):
-            self.assertEqual('OVERRIDDEN CLOUDTYPE', dsrc.get_cloud_type())
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", cloud_info):
+            self.assertEqual("OVERRIDDEN CLOUDTYPE", dsrc.get_cloud_type())
 
     def test_rhev(self):
-        '''
+        """
         Test method get_cloud_type() for RHEVm systems.
         Forcing read_dmi_data return to match a RHEVm system: RHEV Hypervisor
-        '''
-        dmi.read_dmi_data = _dmi_data('RHEV')
+        """
+        dmi.read_dmi_data = _dmi_data("RHEV")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        self.assertEqual('RHEV', dsrc.get_cloud_type())
+        self.assertEqual("RHEV", dsrc.get_cloud_type())
 
     def test_vsphere(self):
-        '''
+        """
         Test method get_cloud_type() for vSphere systems.
         Forcing read_dmi_data return to match a vSphere system: RHEV Hypervisor
-        '''
-        dmi.read_dmi_data = _dmi_data('VMware Virtual Platform')
+        """
+        dmi.read_dmi_data = _dmi_data("VMware Virtual Platform")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        self.assertEqual('VSPHERE', dsrc.get_cloud_type())
+        self.assertEqual("VSPHERE", dsrc.get_cloud_type())
 
     def test_unknown(self):
-        '''
+        """
         Test method get_cloud_type() for unknown systems.
         Forcing read_dmi_data return to match an unrecognized return.
-        '''
-        dmi.read_dmi_data = _dmi_data('Unrecognized Platform')
+        """
+        dmi.read_dmi_data = _dmi_data("Unrecognized Platform")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        self.assertEqual('UNKNOWN', dsrc.get_cloud_type())
+        self.assertEqual("UNKNOWN", dsrc.get_cloud_type())
 
 
 class TestGetDataCloudInfoFile(CiTestCase):
-    '''
+    """
     Test to exercise method: DataSourceAltCloud.get_data()
     With a contrived CLOUD_INFO_FILE
-    '''
+    """
+
     def setUp(self):
-        '''Set up.'''
+        """Set up."""
         self.tmp = self.tmp_dir()
         self.paths = helpers.Paths(
-            {'cloud_dir': self.tmp, 'run_dir': self.tmp})
-        self.cloud_info_file = self.tmp_path('cloud-info', dir=self.tmp)
+            {"cloud_dir": self.tmp, "run_dir": self.tmp}
+        )
+        self.cloud_info_file = self.tmp_path("cloud-info", dir=self.tmp)
 
     def test_rhev(self):
-        '''Success Test module get_data() forcing RHEV.'''
+        """Success Test module get_data() forcing RHEV."""
 
-        util.write_file(self.cloud_info_file, 'RHEV')
+        util.write_file(self.cloud_info_file, "RHEV")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_rhevm = lambda: True
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.cloud_info_file):
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.cloud_info_file):
             self.assertEqual(True, dsrc.get_data())
-        self.assertEqual('altcloud', dsrc.cloud_name)
-        self.assertEqual('altcloud', dsrc.platform_type)
-        self.assertEqual('rhev (/dev/fd0)', dsrc.subplatform)
+        self.assertEqual("altcloud", dsrc.cloud_name)
+        self.assertEqual("altcloud", dsrc.platform_type)
+        self.assertEqual("rhev (/dev/fd0)", dsrc.subplatform)
 
     def test_vsphere(self):
-        '''Success Test module get_data() forcing VSPHERE.'''
+        """Success Test module get_data() forcing VSPHERE."""
 
-        util.write_file(self.cloud_info_file, 'VSPHERE')
+        util.write_file(self.cloud_info_file, "VSPHERE")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_vsphere = lambda: True
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.cloud_info_file):
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.cloud_info_file):
             self.assertEqual(True, dsrc.get_data())
-        self.assertEqual('altcloud', dsrc.cloud_name)
-        self.assertEqual('altcloud', dsrc.platform_type)
-        self.assertEqual('vsphere (unknown)', dsrc.subplatform)
+        self.assertEqual("altcloud", dsrc.cloud_name)
+        self.assertEqual("altcloud", dsrc.platform_type)
+        self.assertEqual("vsphere (unknown)", dsrc.subplatform)
 
     def test_fail_rhev(self):
-        '''Failure Test module get_data() forcing RHEV.'''
+        """Failure Test module get_data() forcing RHEV."""
 
-        util.write_file(self.cloud_info_file, 'RHEV')
+        util.write_file(self.cloud_info_file, "RHEV")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_rhevm = lambda: False
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.cloud_info_file):
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.cloud_info_file):
             self.assertEqual(False, dsrc.get_data())
 
     def test_fail_vsphere(self):
-        '''Failure Test module get_data() forcing VSPHERE.'''
+        """Failure Test module get_data() forcing VSPHERE."""
 
-        util.write_file(self.cloud_info_file, 'VSPHERE')
+        util.write_file(self.cloud_info_file, "VSPHERE")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_vsphere = lambda: False
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.cloud_info_file):
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.cloud_info_file):
             self.assertEqual(False, dsrc.get_data())
 
     def test_unrecognized(self):
-        '''Failure Test module get_data() forcing unrecognized.'''
+        """Failure Test module get_data() forcing unrecognized."""
 
-        util.write_file(self.cloud_info_file, 'unrecognized')
+        util.write_file(self.cloud_info_file, "unrecognized")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        with mock.patch.object(dsac, 'CLOUD_INFO_FILE', self.cloud_info_file):
+        with mock.patch.object(dsac, "CLOUD_INFO_FILE", self.cloud_info_file):
             self.assertEqual(False, dsrc.get_data())
 
 
 class TestGetDataNoCloudInfoFile(CiTestCase):
-    '''
+    """
     Test to exercise method: DataSourceAltCloud.get_data()
     Without a CLOUD_INFO_FILE
-    '''
+    """
+
     def setUp(self):
-        '''Set up.'''
+        """Set up."""
         self.tmp = self.tmp_dir()
         self.paths = helpers.Paths(
-            {'cloud_dir': self.tmp, 'run_dir': self.tmp})
+            {"cloud_dir": self.tmp, "run_dir": self.tmp}
+        )
         self.dmi_data = dmi.read_dmi_data
-        dsac.CLOUD_INFO_FILE = \
-            'no such file'
+        dsac.CLOUD_INFO_FILE = "no such file"
         # We have a different code path for arm to deal with LP1243287
         # We have to switch arch to x86_64 to avoid test failure
-        force_arch('x86_64')
+        force_arch("x86_64")
 
     def tearDown(self):
         # Reset
-        dsac.CLOUD_INFO_FILE = \
-            '/etc/sysconfig/cloud-info'
+        dsac.CLOUD_INFO_FILE = "/etc/sysconfig/cloud-info"
         dmi.read_dmi_data = self.dmi_data
         # Return back to original arch
         force_arch()
 
     def test_rhev_no_cloud_file(self):
-        '''Test No cloud info file module get_data() forcing RHEV.'''
+        """Test No cloud info file module get_data() forcing RHEV."""
 
-        dmi.read_dmi_data = _dmi_data('RHEV Hypervisor')
+        dmi.read_dmi_data = _dmi_data("RHEV Hypervisor")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_rhevm = lambda: True
         self.assertEqual(True, dsrc.get_data())
 
     def test_vsphere_no_cloud_file(self):
-        '''Test No cloud info file module get_data() forcing VSPHERE.'''
+        """Test No cloud info file module get_data() forcing VSPHERE."""
 
-        dmi.read_dmi_data = _dmi_data('VMware Virtual Platform')
+        dmi.read_dmi_data = _dmi_data("VMware Virtual Platform")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         dsrc.user_data_vsphere = lambda: True
         self.assertEqual(True, dsrc.get_data())
 
     def test_failure_no_cloud_file(self):
-        '''Test No cloud info file module get_data() forcing unrecognized.'''
+        """Test No cloud info file module get_data() forcing unrecognized."""
 
-        dmi.read_dmi_data = _dmi_data('Unrecognized Platform')
+        dmi.read_dmi_data = _dmi_data("Unrecognized Platform")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         self.assertEqual(False, dsrc.get_data())
 
 
 class TestUserDataRhevm(CiTestCase):
-    '''
+    """
     Test to exercise method: DataSourceAltCloud.user_data_rhevm()
-    '''
+    """
+
     def setUp(self):
-        '''Set up.'''
-        self.paths = helpers.Paths({'cloud_dir': '/tmp'})
+        """Set up."""
+        self.paths = helpers.Paths({"cloud_dir": "/tmp"})
         self.mount_dir = self.tmp_dir()
-        _write_user_data_files(self.mount_dir, 'test user data')
+        _write_user_data_files(self.mount_dir, "test user data")
         self.add_patch(
-            'cloudinit.sources.DataSourceAltCloud.modprobe_floppy',
-            'm_modprobe_floppy', return_value=None)
+            "cloudinit.sources.DataSourceAltCloud.modprobe_floppy",
+            "m_modprobe_floppy",
+            return_value=None,
+        )
         self.add_patch(
-            'cloudinit.sources.DataSourceAltCloud.util.udevadm_settle',
-            'm_udevadm_settle', return_value=('', ''))
+            "cloudinit.sources.DataSourceAltCloud.util.udevadm_settle",
+            "m_udevadm_settle",
+            return_value=("", ""),
+        )
         self.add_patch(
-            'cloudinit.sources.DataSourceAltCloud.util.mount_cb',
-            'm_mount_cb')
+            "cloudinit.sources.DataSourceAltCloud.util.mount_cb", "m_mount_cb"
+        )
 
     def test_mount_cb_fails(self):
-        '''Test user_data_rhevm() where mount_cb fails.'''
+        """Test user_data_rhevm() where mount_cb fails."""
 
         self.m_mount_cb.side_effect = util.MountFailedError("Failed Mount")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         self.assertEqual(False, dsrc.user_data_rhevm())
 
     def test_modprobe_fails(self):
-        '''Test user_data_rhevm() where modprobe fails.'''
+        """Test user_data_rhevm() where modprobe fails."""
 
         self.m_modprobe_floppy.side_effect = subp.ProcessExecutionError(
-            "Failed modprobe")
+            "Failed modprobe"
+        )
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         self.assertEqual(False, dsrc.user_data_rhevm())
 
     def test_no_modprobe_cmd(self):
-        '''Test user_data_rhevm() with no modprobe command.'''
+        """Test user_data_rhevm() with no modprobe command."""
 
         self.m_modprobe_floppy.side_effect = subp.ProcessExecutionError(
-            "No such file or dir")
+            "No such file or dir"
+        )
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         self.assertEqual(False, dsrc.user_data_rhevm())
 
     def test_udevadm_fails(self):
-        '''Test user_data_rhevm() where udevadm fails.'''
+        """Test user_data_rhevm() where udevadm fails."""
 
         self.m_udevadm_settle.side_effect = subp.ProcessExecutionError(
-            "Failed settle.")
+            "Failed settle."
+        )
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
         self.assertEqual(False, dsrc.user_data_rhevm())
 
     def test_no_udevadm_cmd(self):
-        '''Test user_data_rhevm() with no udevadm command.'''
+        """Test user_data_rhevm() with no udevadm command."""
 
         self.m_udevadm_settle.side_effect = OSError("No such file or dir")
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
@@ -318,16 +322,17 @@ class TestUserDataRhevm(CiTestCase):
 
 
 class TestUserDataVsphere(CiTestCase):
-    '''
+    """
     Test to exercise method: DataSourceAltCloud.user_data_vsphere()
-    '''
+    """
+
     def setUp(self):
-        '''Set up.'''
+        """Set up."""
         self.tmp = self.tmp_dir()
-        self.paths = helpers.Paths({'cloud_dir': self.tmp})
+        self.paths = helpers.Paths({"cloud_dir": self.tmp})
         self.mount_dir = tempfile.mkdtemp()
 
-        _write_user_data_files(self.mount_dir, 'test user data')
+        _write_user_data_files(self.mount_dir, "test user data")
 
     def tearDown(self):
         # Reset
@@ -340,13 +345,12 @@ class TestUserDataVsphere(CiTestCase):
         except OSError:
             pass
 
-        dsac.CLOUD_INFO_FILE = \
-            '/etc/sysconfig/cloud-info'
+        dsac.CLOUD_INFO_FILE = "/etc/sysconfig/cloud-info"
 
     @mock.patch("cloudinit.sources.DataSourceAltCloud.util.find_devs_with")
     @mock.patch("cloudinit.sources.DataSourceAltCloud.util.mount_cb")
     def test_user_data_vsphere_no_cdrom(self, m_mount_cb, m_find_devs_with):
-        '''Test user_data_vsphere() where mount_cb fails.'''
+        """Test user_data_vsphere() where mount_cb fails."""
 
         m_mount_cb.return_value = []
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
@@ -356,7 +360,7 @@ class TestUserDataVsphere(CiTestCase):
     @mock.patch("cloudinit.sources.DataSourceAltCloud.util.find_devs_with")
     @mock.patch("cloudinit.sources.DataSourceAltCloud.util.mount_cb")
     def test_user_data_vsphere_mcb_fail(self, m_mount_cb, m_find_devs_with):
-        '''Test user_data_vsphere() where mount_cb fails.'''
+        """Test user_data_vsphere() where mount_cb fails."""
 
         m_find_devs_with.return_value = ["/dev/mock/cdrom"]
         m_mount_cb.side_effect = util.MountFailedError("Unable To mount")
@@ -370,28 +374,30 @@ class TestUserDataVsphere(CiTestCase):
     def test_user_data_vsphere_success(self, m_mount_cb, m_find_devs_with):
         """Test user_data_vsphere() where successful."""
         m_find_devs_with.return_value = ["/dev/mock/cdrom"]
-        m_mount_cb.return_value = 'raw userdata from cdrom'
+        m_mount_cb.return_value = "raw userdata from cdrom"
         dsrc = dsac.DataSourceAltCloud({}, None, self.paths)
-        cloud_info = self.tmp_path('cloud-info', dir=self.tmp)
-        util.write_file(cloud_info, 'VSPHERE')
+        cloud_info = self.tmp_path("cloud-info", dir=self.tmp)
+        util.write_file(cloud_info, "VSPHERE")
         self.assertEqual(True, dsrc.user_data_vsphere())
-        m_find_devs_with.assert_called_once_with('LABEL=CDROM')
+        m_find_devs_with.assert_called_once_with("LABEL=CDROM")
         m_mount_cb.assert_called_once_with(
-            '/dev/mock/cdrom', dsac.read_user_data_callback)
-        with mock.patch.object(dsrc, 'get_cloud_type', return_value='VSPHERE'):
-            self.assertEqual('vsphere (/dev/mock/cdrom)', dsrc.subplatform)
+            "/dev/mock/cdrom", dsac.read_user_data_callback
+        )
+        with mock.patch.object(dsrc, "get_cloud_type", return_value="VSPHERE"):
+            self.assertEqual("vsphere (/dev/mock/cdrom)", dsrc.subplatform)
 
 
 class TestReadUserDataCallback(CiTestCase):
-    '''
+    """
     Test to exercise method: DataSourceAltCloud.read_user_data_callback()
-    '''
+    """
+
     def setUp(self):
-        '''Set up.'''
-        self.paths = helpers.Paths({'cloud_dir': '/tmp'})
+        """Set up."""
+        self.paths = helpers.Paths({"cloud_dir": "/tmp"})
         self.mount_dir = tempfile.mkdtemp()
 
-        _write_user_data_files(self.mount_dir, 'test user data')
+        _write_user_data_files(self.mount_dir, "test user data")
 
     def tearDown(self):
         # Reset
@@ -405,46 +411,49 @@ class TestReadUserDataCallback(CiTestCase):
             pass
 
     def test_callback_both(self):
-        '''Test read_user_data_callback() with both files.'''
+        """Test read_user_data_callback() with both files."""
 
-        self.assertEqual('test user data',
-                         dsac.read_user_data_callback(self.mount_dir))
+        self.assertEqual(
+            "test user data", dsac.read_user_data_callback(self.mount_dir)
+        )
 
     def test_callback_dc(self):
-        '''Test read_user_data_callback() with only DC file.'''
+        """Test read_user_data_callback() with only DC file."""
 
-        _remove_user_data_files(self.mount_dir,
-                                dc_file=False,
-                                non_dc_file=True)
+        _remove_user_data_files(
+            self.mount_dir, dc_file=False, non_dc_file=True
+        )
 
-        self.assertEqual('test user data',
-                         dsac.read_user_data_callback(self.mount_dir))
+        self.assertEqual(
+            "test user data", dsac.read_user_data_callback(self.mount_dir)
+        )
 
     def test_callback_non_dc(self):
-        '''Test read_user_data_callback() with only non-DC file.'''
+        """Test read_user_data_callback() with only non-DC file."""
 
-        _remove_user_data_files(self.mount_dir,
-                                dc_file=True,
-                                non_dc_file=False)
+        _remove_user_data_files(
+            self.mount_dir, dc_file=True, non_dc_file=False
+        )
 
-        self.assertEqual('test user data',
-                         dsac.read_user_data_callback(self.mount_dir))
+        self.assertEqual(
+            "test user data", dsac.read_user_data_callback(self.mount_dir)
+        )
 
     def test_callback_none(self):
-        '''Test read_user_data_callback() no files are found.'''
+        """Test read_user_data_callback() no files are found."""
 
         _remove_user_data_files(self.mount_dir)
         self.assertIsNone(dsac.read_user_data_callback(self.mount_dir))
 
 
 def force_arch(arch=None):
-
     def _os_uname():
-        return ('LINUX', 'NODENAME', 'RELEASE', 'VERSION', arch)
+        return ("LINUX", "NODENAME", "RELEASE", "VERSION", arch)
 
     if arch:
-        setattr(os, 'uname', _os_uname)
+        setattr(os, "uname", _os_uname)
     elif arch is None:
-        setattr(os, 'uname', OS_UNAME_ORIG)
+        setattr(os, "uname", OS_UNAME_ORIG)
+
 
 # vi: ts=4 expandtab