Add cleanup and fix pylint errors

mininet/test/test_switchdpidassignment.py

@@ -20,16 +20,23 @@ class testSwitchDpidAssignmentCommon ( object ):
 
     switchClass = None # overridden in subclasses
 
+    def tearDown( self ):
+        "Clean up if necessary"
+        if sys.exc_info != ( None, None, None ):
+            cleanup()
+
     def testDefaultDpid ( self ):
         """Verify that the default dpid is assigned using a valid provided
         canonical switchname if no dpid is passed in switch creation."""
-        switch = Mininet( Topo(), self.switchClass, Host, Controller ).addSwitch( 's1' )
+        switch = Mininet( Topo(),
+                          self.switchClass, Host, Controller ).addSwitch( 's1' )
         self.assertEqual( switch.defaultDpid(), switch.dpid )
 
     def testActualDpidAssignment( self ):
         """Verify that Switch dpid is the actual dpid assigned if dpid is
         passed in switch creation."""
-        switch = Mininet( Topo(), self.switchClass, Host, Controller ).addSwitch( 'A', dpid = '000000000000ABCD' )
+        switch = Mininet( Topo(), self.switchClass,
+                          Host, Controller ).addSwitch( 'A', dpid = '000000000000ABCD' )
         self.assertEqual( switch.dpid, '000000000000ABCD' )
 
     def testDefaultDpidAssignmentFailure( self ):
@@ -37,7 +44,8 @@ def testDefaultDpidAssignmentFailure( self ):
         name of the switch does not contin a digit. Also verify the
         exception message."""
         with self.assertRaises( Exception ) as raises_cm:
-            Mininet( Topo(), self.switchClass, Host, Controller ).addSwitch( 'A' )
+            Mininet( Topo(), self.switchClass,
+                     Host, Controller ).addSwitch( 'A' )
         self.assertEqual(raises_cm.exception.message, 'Unable to derive '
                          'default datapath ID - please either specify a dpid '
                          'or use a canonical switch name such as s23.')
@@ -47,17 +55,21 @@ def testDefaultDpidLen( self ):
         16 - len(hex of first string of contiguous digits passed in switch
         name) 0's followed by hex of first string of contiguous digits passed
         in switch name."""
-        switch = Mininet( Topo(), self.switchClass, Host, Controller ).addSwitch( 's123' )
+        switch = Mininet( Topo(), self.switchClass,
+                          Host, Controller ).addSwitch( 's123' )
         dpid = hex( int(re.findall( r'\d+', switch.name ) [0]) ) [ 2: ]
         try:
             if issubclass(UserSwitch, self.switchClass):
                 # Dpid lenght of UserSwitch = 12
-                self.assertEqual( switch.dpid, '0' * (12 - len(dpid)) + str(dpid) )
+                self.assertEqual( switch.dpid,
+                                  '0' * (12 - len(dpid)) + str(dpid) )
             else:
-                self.assertEqual( switch.dpid, '0' * (16 - len(dpid)) + str(dpid) )
+                self.assertEqual( switch.dpid,
+                                  '0' * (16 - len(dpid)) + str(dpid) )
         except TypeError:
             # Switch is OVS User Switch
-            self.assertEqual( switch.dpid, '0' * (16 - len(dpid)) + str(dpid) )
+            self.assertEqual( switch.dpid,
+                              '0' * (16 - len(dpid)) + str(dpid) )
 
 
 class testSwitchOVSKernel( testSwitchDpidAssignmentCommon, unittest.TestCase ):
@@ -68,18 +80,22 @@ class testSwitchOVSUser( testSwitchDpidAssignmentCommon, unittest.TestCase ):
     """Test dpid assignnment of OVS User Switch."""
     switchClass = partial(OVSSwitch, datapath = 'user')
 
-@unittest.skipUnless( quietRun( 'which ovs-openflowd' ), 'OVS Legacy Kernel switch is not installed' )
-class testSwitchOVSLegacyKernel( testSwitchDpidAssignmentCommon, unittest.TestCase ):
+@unittest.skipUnless( quietRun( 'which ovs-openflowd' ),
+                      'OVS Legacy Kernel switch is not installed' )
+class testSwitchOVSLegacyKernel( testSwitchDpidAssignmentCommon,
+                                 unittest.TestCase ):
     """Test dpid assignnment of OVS Legacy Kernel Switch."""
     switchClass = OVSLegacyKernelSwitch
 
 @unittest.skipUnless( quietRun( 'which ivs-ctl' ), 'IVS switch is not installed' )
-class testSwitchIVS( testSwitchDpidAssignmentCommon, unittest.TestCase ):
+class testSwitchIVS( testSwitchDpidAssignmentCommon,
+                     unittest.TestCase ):
     """Test dpid assignment of IVS switch."""
     switchClass = IVSSwitch
 
 @unittest.skipUnless( quietRun( 'which ofprotocol' ), 'Reference user switch is not installed' )
-class testSwitchUserspace( testSwitchDpidAssignmentCommon, unittest.TestCase ):
+class testSwitchUserspace( testSwitchDpidAssignmentCommon,
+                           unittest.TestCase ):
     """Test dpid assignment of Userspace switch."""
     switchClass = UserSwitch