More pylint changes

examples/cluster.py

@@ -123,7 +123,8 @@ class RemoteMixin( object ):
            **kwargs: see Node()"""
         # We connect to servers by IP address
         self.server = server if server else 'localhost'
-        self.serverIP = serverIP if serverIP else self.findServerIP( self.server )
+        self.serverIP = ( serverIP if serverIP
+                          else self.findServerIP( self.server ) )
         self.user = user if user else self.findUser()
         if controlPath is True:
             # Set a default control path for shared SSH connections
@@ -143,21 +144,20 @@ class RemoteMixin( object ):
             self.dest = None
             self.sshcmd = []
             self.isRemote = False
+        # Satisfy pylint
+        self.shell, self.pid, self.cmd = None, None, None
         super( RemoteMixin, self ).__init__( name, **kwargs )
 
     @staticmethod
     def findUser():
         "Try to return logged-in (usually non-root) user"
-        try:
+        return (
             # If we're running sudo
-            return os.environ[ 'SUDO_USER' ]
+            os.environ.get( 'SUDO_USER', False ) or
-        except:
-            try:
             # Logged-in user (if we have a tty)
-                return quietRun( 'who am i' ).split()[ 0 ]
+            ( quietRun( 'who am i' ).split() or [ False ] )[ 0 ] or
-            except:
             # Give up and return effective user
-                return quietRun( 'whoami' )
+            quietRun( 'whoami' ) )
 
     # Determine IP address of local host
     _ipMatchRegex = re.compile( r'\d+\.\d+\.\d+\.\d+' )
@@ -187,6 +187,8 @@ class RemoteMixin( object ):
             self.pid = int( self.cmd( 'echo $$' ) )
 
     def finishInit( self ):
+        "Wait for split initialization to complete"
+        assert self  # please pylint
         self.pid = int( self.waitOutput() )
 
     def rpopen( self, *cmd, **opts ):
@@ -282,7 +284,8 @@ class RemoteOVSSwitch( RemoteMixin, OVSSwitch ):
         cls = type( self )
         if self.server not in cls.OVSVersions:
             vers = self.cmd( 'ovs-vsctl --version' )
-            cls.OVSVersions[ self.server ] = re.findall( r'\d+\.\d+', vers )[ 0 ]
+            cls.OVSVersions[ self.server ] = re.findall(
+                r'\d+\.\d+', vers )[ 0 ]
         return ( StrictVersion( cls.OVSVersions[ self.server ] ) <
                 StrictVersion( '1.10' ) )
 
@@ -301,6 +304,7 @@ class RemoteLink( Link ):
         self.tunnel = None
         kwargs.setdefault( 'params1', {} )
         kwargs.setdefault( 'params2', {} )
+        self.cmd = None  # satisfy pylint
         Link.__init__( self, node1, node2, **kwargs )
 
     def stop( self ):
@@ -324,9 +328,10 @@ class RemoteLink( Link ):
         elif server1 == server2:
             # Remote link on same remote server
             return makeIntfPair( intfname1, intfname2, addr1, addr2,
-                                 run=node1.rcmd )
+                                 runCmd=node1.rcmd )
         # Otherwise, make a tunnel
-        self.tunnel = self.makeTunnel( node1, node2, intfname1, intfname2, addr1, addr2 )
+        self.tunnel = self.makeTunnel( node1, node2, intfname1, intfname2,
+                                       addr1, addr2 )
         return self.tunnel
 
     @staticmethod
@@ -340,7 +345,7 @@ class RemoteLink( Link ):
         cmd = 'ip link set %s netns %s' % ( intf, node.pid )
         node.rcmd( cmd )
         links = node.cmd( 'ip link show' )
-        if not ( ' %s:' % intf ) in links:
+        if not ' %s:' % intf in links:
             if printError:
                 error( '*** Error: RemoteLink.moveIntf: ' + intf +
                       ' not successfully moved to ' + node.name + '\n' )
@@ -442,8 +447,9 @@ class Placer( object ):
 
     def place( self, node ):
         "Return server for a given node"
+        assert self, node  # satisfy pylint
         # Default placement: run locally
-        return None
+        return 'localhost'
 
 
 class RandomPlacer( Placer ):
@@ -451,6 +457,7 @@ class RandomPlacer( Placer ):
     def place( self, nodename ):
         """Random placement function
             nodename: node name"""
+        assert nodename  # please pylint
         # This may be slow with lots of servers
         return self.servers[ randrange( 0, len( self.servers ) ) ]
 
@@ -467,6 +474,7 @@ class RoundRobinPlacer( Placer ):
     def place( self, nodename ):
         """Round-robin placement function
             nodename: node name"""
+        assert nodename  # please pylint
         # This may be slow with lots of servers
         server = self.servers[ self.next ]
         self.next = ( self.next + 1 ) % len( self.servers )
@@ -626,6 +634,7 @@ class MininetCluster( Mininet ):
 
     def popen( self, cmd ):
         "Popen() for server connections"
+        assert self  # please pylint
         old = signal( SIGINT, SIG_IGN )
         conn = Popen( cmd, stdin=PIPE, stdout=PIPE, close_fds=True )
         signal( SIGINT, old )
@@ -649,7 +658,7 @@ class MininetCluster( Mininet ):
             cmd = [ 'sudo', '-E', '-u', self.user ]
             cmd += self.sshcmd + [ '-n', dest, 'sudo true' ]
             debug( ' '.join( cmd ), '\n' )
-            out, err, code = errRun( cmd )
+            _out, _err, code = errRun( cmd )
             if code != 0:
                 error( '\nstartConnection: server connection check failed '
                        'to %s using command:\n%s\n'
@@ -665,6 +674,7 @@ class MininetCluster( Mininet ):
 
     def modifiedaddHost( self, *args, **kwargs ):
         "Slightly modify addHost"
+        assert self  # please pylint
         kwargs[ 'splitInit' ] = True
         return Mininet.addHost( *args, **kwargs )
 

examples/clustercli.py

@@ -5,6 +5,7 @@
 from mininet.cli import CLI
 from mininet.log import output, error
 
+# pylint: disable=global-statement
 nx, graphviz_layout, plt = None, None, None  # Will be imported on demand
 
 
@@ -23,17 +24,19 @@ class ClusterCLI( CLI ):
         colors = colors[ 0 : slen ]
         return colors
 
-    def do_plot( self, line ):
+    def do_plot( self, _line ):
         "Plot topology colored by node placement"
         # Import networkx if needed
         global nx, plt
         if not nx:
             try:
-                import networkx as nx
+                import networkx
-                import matplotlib.pyplot as plt
+                nx = networkx  # satisfy pylint
+                from matplotlib import pyplot
+                plt = pyplot   # satisfiy pylint
                 import pygraphviz
                 assert pygraphviz  # silence pyflakes
-            except:
+            except ImportError:
                 error( 'plot requires networkx, matplotlib and pygraphviz - '
                        'please install them and try again\n' )
                 return
@@ -53,10 +56,13 @@ class ClusterCLI( CLI ):
         pos = nx.graphviz_layout( g )
         opts = { 'ax': None, 'font_weight': 'bold',
 		 'width': 2, 'edge_color': 'darkblue' }
-        hcolors = [ color[ getattr( h, 'server', 'localhost' ) ] for h in hosts ]
+        hcolors = [ color[ getattr( h, 'server', 'localhost' ) ]
-        scolors = [ color[ getattr( s, 'server', 'localhost' ) ] for s in switches ]
+                    for h in hosts ]
-        nx.draw_networkx( g, pos=pos, nodelist=hosts, node_size=800, label='host',
+        scolors = [ color[ getattr( s, 'server', 'localhost' ) ]
-                          node_color=hcolors, node_shape='s', **opts )
+                    for s in switches ]
+        nx.draw_networkx( g, pos=pos, nodelist=hosts, node_size=800,
+                          label='host', node_color=hcolors, node_shape='s',
+                          **opts )
         nx.draw_networkx( g, pos=pos, nodelist=switches, node_size=1000,
                           node_color=scolors, node_shape='o', **opts )
         # Get rid of axes, add title, and show
@@ -68,7 +74,7 @@ class ClusterCLI( CLI ):
         plt.title( 'Node Placement', fontweight='bold' )
         plt.show()
 
-    def do_status( self, line ):
+    def do_status( self, _line ):
         "Report on node shell status"
         nodes = self.mn.hosts + self.mn.switches
         for node in nodes:
@@ -83,7 +89,7 @@ class ClusterCLI( CLI ):
             output( 'All nodes are still running.\n' )
 
 
-    def do_placement( self, line ):
+    def do_placement( self, _line ):
         "Describe node placement"
         mn = self.mn
         nodes = mn.hosts + mn.switches + mn.controllers

examples/limit.py

@@ -27,9 +27,11 @@ def limit( bw=10, cpu=.1 ):
         info( '*** Testing with', sched, 'bandwidth limiting\n' )
         if sched == 'rt':
             release = quietRun( 'uname -r' ).strip('\r\n')
-            output = quietRun( 'grep CONFIG_RT_GROUP_SCHED /boot/config-%s' % release )
+            output = quietRun( 'grep CONFIG_RT_GROUP_SCHED /boot/config-%s'
+                               % release )
             if output == '# CONFIG_RT_GROUP_SCHED is not set\n':
-                info( '*** RT Scheduler is not enabled in your kernel. Skipping this test\n' )
+                info( '*** RT Scheduler is not enabled in your kernel. '
+                      'Skipping this test\n' )
                 continue
         host = custom( CPULimitedHost, sched=sched, cpu=cpu )
         net = Mininet( topo=myTopo, intf=intf, host=host )

examples/linuxrouter.py

@@ -44,16 +44,23 @@ class LinuxRouter( Node ):
 class NetworkTopo( Topo ):
     "A simple topology of a router with three subnets (one host in each)."
 
-    def build( self, n=2, h=1, **opts ):
+    def build( self, **opts ):
         router = self.addNode( 'r0', cls=LinuxRouter, ip='192.168.1.1/24' )
-        h1 = self.addHost( 'h1', ip='192.168.1.100/24', defaultRoute='via 192.168.1.1' )
+        h1 = self.addHost( 'h1', ip='192.168.1.100/24',
-        h2 = self.addHost( 'h2', ip='172.16.0.100/12', defaultRoute='via 172.16.0.1' )
+                           defaultRoute='via 192.168.1.1' )
-        h3 = self.addHost( 'h3', ip='10.0.0.100/8', defaultRoute='via 10.0.0.1' )
+        h2 = self.addHost( 'h2', ip='172.16.0.100/12',
-        self.addLink( h1, router, intfName2='r0-eth1', params2={ 'ip' : '192.168.1.1/24' } )
+                           defaultRoute='via 172.16.0.1' )
-        self.addLink( h2, router, intfName2='r0-eth2', params2={ 'ip' : '172.16.0.1/12' } )
+        h3 = self.addHost( 'h3', ip='10.0.0.100/8',
-        self.addLink( h3, router, intfName2='r0-eth3', params2={ 'ip' : '10.0.0.1/8' } )
+                           defaultRoute='via 10.0.0.1' )
+        self.addLink( h1, router, intfName2='r0-eth1',
+                      params2={ 'ip' : '192.168.1.1/24' } )
+        self.addLink( h2, router, intfName2='r0-eth2',
+                      params2={ 'ip' : '172.16.0.1/12' } )
+        self.addLink( h3, router, intfName2='r0-eth3',
+                      params2={ 'ip' : '10.0.0.1/8' } )
 
 def run():
+    "Test linux router"
     topo = NetworkTopo()
     net = Mininet( topo=topo, controller=None ) # no controller needed
     net.start()

examples/miniedit.py

@@ -13,6 +13,9 @@ Controller icon from http://semlabs.co.uk/
 OpenFlow icon from https://www.opennetworking.org/
 """
 
+# For now, tolerate long lines and long module
+# pylint: disable=line-too-long,too-many-lines
+
 MINIEDIT_VERSION = '2.2.0.1'
 
 from optparse import OptionParser
@@ -83,34 +86,38 @@ HOSTS = { 'proc': Host,
 
 
 class InbandController( RemoteController ):
-
+    "RemoteController that ignores checkListening"
     def checkListening( self ):
         "Overridden to do nothing."
         return
 
 class CustomUserSwitch(UserSwitch):
+    "Customized UserSwitch"
     def __init__( self, name, dpopts='--no-slicing', **kwargs ):
         UserSwitch.__init__( self, name, **kwargs )
         self.switchIP = None
 
     def getSwitchIP(self):
+        "Return management IP address"
         return self.switchIP
 
     def setSwitchIP(self, ip):
+        "Set management IP address"
         self.switchIP = ip
 
     def start( self, controllers ):
+        "Start and set management IP address"
         # Call superclass constructor
         UserSwitch.start( self, controllers )
         # Set Switch IP address
-        if (self.switchIP is not None):
+        if self.switchIP is not None:
             if not self.inNamespace:
                 self.cmd( 'ifconfig', self, self.switchIP )
             else:
                 self.cmd( 'ifconfig lo', self.switchIP )
 
 class LegacyRouter( Node ):
-
+    "Simple IP router"
     def __init__( self, name, inNamespace=True, **params ):
         Node.__init__( self, name, inNamespace, **params )
 
@@ -122,31 +129,36 @@ class LegacyRouter( Node ):
         return r
 
 class LegacySwitch(OVSSwitch):
-
+    "OVS switch in standalone/bridge mode"
     def __init__( self, name, **params ):
         OVSSwitch.__init__( self, name, failMode='standalone', **params )
         self.switchIP = None
 
 class customOvs(OVSSwitch):
+    "Customized OVS switch"
 
     def __init__( self, name, failMode='secure', datapath='kernel', **params ):
         OVSSwitch.__init__( self, name, failMode=failMode, datapath=datapath, **params )
         self.switchIP = None
 
     def getSwitchIP(self):
+        "Return management IP address"
         return self.switchIP
 
     def setSwitchIP(self, ip):
+        "Set management IP address"
         self.switchIP = ip
 
     def start( self, controllers ):
+        "Start and set management IP address"
         # Call superclass constructor
         OVSSwitch.start( self, controllers )
         # Set Switch IP address
-        if (self.switchIP is not None):
+        if self.switchIP is not None:
             self.cmd( 'ifconfig', self, self.switchIP )
 
 class PrefsDialog(tkSimpleDialog.Dialog):
+    "Preferences dialog"
 
     def __init__(self, parent, title, prefDefaults):
 
@@ -155,13 +167,13 @@ class PrefsDialog(tkSimpleDialog.Dialog):
         tkSimpleDialog.Dialog.__init__(self, parent, title)
 
     def body(self, master):
+        "Create dialog body"
         self.rootFrame = master
         self.leftfieldFrame = Frame(self.rootFrame, padx=5, pady=5)
         self.leftfieldFrame.grid(row=0, column=0, sticky='nswe', columnspan=2)
         self.rightfieldFrame = Frame(self.rootFrame, padx=5, pady=5)
         self.rightfieldFrame.grid(row=0, column=2, sticky='nswe', columnspan=2)
 
-
         # Field for Base IP
         Label(self.leftfieldFrame, text="IP Base:").grid(row=0, sticky=E)
         self.ipEntry = Entry(self.leftfieldFrame)
@@ -363,6 +375,7 @@ class PrefsDialog(tkSimpleDialog.Dialog):
             self.result = None
 
     def getOvsVersion(self):
+        "Return OVS version"
         outp = quietRun("ovs-vsctl show")
         r = r'ovs_version: "(.*)"'
         m = re.search(r, outp)
@@ -572,8 +585,8 @@ class HostDialog(CustomDialog):
                 vlanInterfaces.append([self.vlanTableFrame.get(row, 0), self.vlanTableFrame.get(row, 1)])
         privateDirectories = []
         for row in range(self.mountTableFrame.rows):
-                if (len(self.mountTableFrame.get(row, 0)) > 0 and row > 0):
+            if len(self.mountTableFrame.get(row, 0)) > 0 and row > 0:
-                    if(len(self.mountTableFrame.get(row, 1)) > 0):
+                if len(self.mountTableFrame.get(row, 1)) > 0:
                     privateDirectories.append((self.mountTableFrame.get(row, 0), self.mountTableFrame.get(row, 1)))
                 else:
                     privateDirectories.append(self.mountTableFrame.get(row, 0))
@@ -739,7 +752,7 @@ class SwitchDialog(CustomDialog):
         externalInterfaces = []
         for row in range(self.tableFrame.rows):
             #print 'Interface is ' + self.tableFrame.get(row, 0)
-                if (len(self.tableFrame.get(row, 0)) > 0):
+            if len(self.tableFrame.get(row, 0)) > 0:
                 externalInterfaces.append(self.tableFrame.get(row, 0))
 
         dpid = self.dpidEntry.get()
@@ -856,7 +869,7 @@ class TableFrame(Frame):
             label.grid(row=self.rows, column=column, sticky="wens", padx=1, pady=1)
             if value is not None:
                 label.insert(0, value[column])
-            if (readonly == True):
+            if readonly == True:
                 label.configure(state='readonly')
             current_row.append(label)
         self._widgets.append(current_row)
@@ -916,17 +929,17 @@ class LinkDialog(tkSimpleDialog.Dialog):
 
     def apply(self):
         self.result = {}
-            if (len(self.e1.get()) > 0):
+        if len(self.e1.get()) > 0:
             self.result['bw'] = int(self.e1.get())
-            if (len(self.e2.get()) > 0):
+        if len(self.e2.get()) > 0:
             self.result['delay'] = self.e2.get()
-            if (len(self.e3.get()) > 0):
+        if len(self.e3.get()) > 0:
             self.result['loss'] = int(self.e3.get())
-            if (len(self.e4.get()) > 0):
+        if len(self.e4.get()) > 0:
             self.result['max_queue_size'] = int(self.e4.get())
-            if (len(self.e5.get()) > 0):
+        if len(self.e5.get()) > 0:
             self.result['jitter'] = self.e5.get()
-            if (len(self.e6.get()) > 0):
+        if len(self.e6.get()) > 0:
             self.result['speedup'] = int(self.e6.get())
 
 class ControllerDialog(tkSimpleDialog.Dialog):
@@ -1427,8 +1440,8 @@ class MiniEdit( Frame ):
                 self.appPrefs["netflow"] = self.nflowDefaults
 
         # Load controllers
-        if ('controllers' in loadedTopology):
+        if 'controllers' in loadedTopology:
-            if (loadedTopology['version'] == '1'):
+            if loadedTopology['version'] == '1':
                 # This is old location of controller info
                 hostname = 'c0'
                 self.controllers = {}
@@ -1509,7 +1522,7 @@ class MiniEdit( Frame ):
             self.switchOpts[hostname] = switch['opts']
 
             # create links to controllers
-            if (int(loadedTopology['version']) > 1):
+            if int(loadedTopology['version']) > 1:
                 controllers = self.switchOpts[hostname]['controllers']
                 for controller in controllers:
                     dest = self.findWidgetByName(controller)
@@ -1774,7 +1787,7 @@ class MiniEdit( Frame ):
                     if 'dpid' in opts:
                         f.write(", dpid='"+opts['dpid']+"'")
                     f.write(")\n")
-                    if ('externalInterfaces' in opts):
+                    if 'externalInterfaces' in opts:
                         for extInterface in opts['externalInterfaces']:
                             f.write("    Intf( '"+extInterface+"', node="+name+" )\n")
 
@@ -1806,7 +1819,7 @@ class MiniEdit( Frame ):
                             f.write("    "+name+".setCPUFrac(f="+str(opts['cpu'])+", sched='"+opts['sched']+"')\n")
                     else:
                         f.write("    "+name+" = net.addHost('"+name+"', cls=Host, ip='"+ip+"', defaultRoute="+defaultRoute+")\n")
-                    if ('externalInterfaces' in opts):
+                    if 'externalInterfaces' in opts:
                         for extInterface in opts['externalInterfaces']:
                             f.write("    Intf( '"+extInterface+"', node="+name+" )\n")
             f.write("\n")
@@ -1893,28 +1906,28 @@ class MiniEdit( Frame ):
                     opts = self.switchOpts[name]
                     if opts['switchType'] == 'default':
                         if self.appPrefs['switchType'] == 'user':
-                            if ('switchIP' in opts):
+                            if 'switchIP' in opts:
-                                if (len(opts['switchIP'])>0):
+                                if len(opts['switchIP']) > 0:
                                     f.write("    "+name+".cmd('ifconfig "+name+" "+opts['switchIP']+"')\n")
                         elif self.appPrefs['switchType'] == 'userns':
-                            if ('switchIP' in opts):
+                            if 'switchIP' in opts:
-                                if (len(opts['switchIP'])>0):
+                                if len(opts['switchIP']) > 0:
                                     f.write("    "+name+".cmd('ifconfig lo "+opts['switchIP']+"')\n")
                         elif self.appPrefs['switchType'] == 'ovs':
-                            if ('switchIP' in opts):
+                            if 'switchIP' in opts:
-                                if (len(opts['switchIP'])>0):
+                                if len(opts['switchIP']) > 0:
                                     f.write("    "+name+".cmd('ifconfig "+name+" "+opts['switchIP']+"')\n")
                     elif opts['switchType'] == 'user':
-                        if ('switchIP' in opts):
+                        if 'switchIP' in opts:
-                            if (len(opts['switchIP'])>0):
+                            if len(opts['switchIP']) > 0:
                                 f.write("    "+name+".cmd('ifconfig "+name+" "+opts['switchIP']+"')\n")
                     elif opts['switchType'] == 'userns':
-                        if ('switchIP' in opts):
+                        if 'switchIP' in opts:
-                            if (len(opts['switchIP'])>0):
+                            if len(opts['switchIP']) > 0:
                                 f.write("    "+name+".cmd('ifconfig lo "+opts['switchIP']+"')\n")
                     elif opts['switchType'] == 'ovs':
-                        if ('switchIP' in opts):
+                        if 'switchIP' in opts:
-                            if (len(opts['switchIP'])>0):
+                            if len(opts['switchIP']) > 0:
                                 f.write("    "+name+".cmd('ifconfig "+name+" "+opts['switchIP']+"')\n")
             for widget in self.widgetToItem:
                 name = widget[ 'text' ]
@@ -1922,17 +1935,17 @@ class MiniEdit( Frame ):
                 if 'Host' in tags:
                     opts = self.hostOpts[name]
                     # Attach vlan interfaces
-                    if ('vlanInterfaces' in opts):
+                    if 'vlanInterfaces' in opts:
                         for vlanInterface in opts['vlanInterfaces']:
                             f.write("    "+name+".cmd('vconfig add "+name+"-eth0 "+vlanInterface[1]+"')\n")
                             f.write("    "+name+".cmd('ifconfig "+name+"-eth0."+vlanInterface[1]+" "+vlanInterface[0]+"')\n")
                     # Run User Defined Start Command
-                    if ('startCommand' in opts):
+                    if 'startCommand' in opts:
                         f.write("    "+name+".cmdPrint('"+opts['startCommand']+"')\n")
                 if 'Switch' in tags:
                     opts = self.switchOpts[name]
                     # Run User Defined Start Command
-                    if ('startCommand' in opts):
+                    if 'startCommand' in opts:
                         f.write("    "+name+".cmdPrint('"+opts['startCommand']+"')\n")
 
             # Configure NetFlow
@@ -1987,12 +2000,12 @@ class MiniEdit( Frame ):
                 if 'Host' in tags:
                     opts = self.hostOpts[name]
                     # Run User Defined Stop Command
-                    if ('stopCommand' in opts):
+                    if 'stopCommand' in opts:
                         f.write("    "+name+".cmdPrint('"+opts['stopCommand']+"')\n")
                 if 'Switch' in tags:
                     opts = self.switchOpts[name]
                     # Run User Defined Stop Command
-                    if ('stopCommand' in opts):
+                    if 'stopCommand' in opts:
                         f.write("    "+name+".cmdPrint('"+opts['stopCommand']+"')\n")
 
             f.write("    net.stop()\n")
@@ -2725,16 +2738,16 @@ class MiniEdit( Frame ):
 
                 # Some post startup config
                 if switchClass == CustomUserSwitch:
-                    if ('switchIP' in opts):
+                    if 'switchIP' in opts:
-                        if (len(opts['switchIP']) > 0):
+                        if len(opts['switchIP']) > 0:
                             newSwitch.setSwitchIP(opts['switchIP'])
                 if switchClass == customOvs:
-                    if ('switchIP' in opts):
+                    if 'switchIP' in opts:
-                        if (len(opts['switchIP']) > 0):
+                        if len(opts['switchIP']) > 0:
                             newSwitch.setSwitchIP(opts['switchIP'])
 
                 # Attach external interfaces
-                if ('externalInterfaces' in opts):
+                if 'externalInterfaces' in opts:
                     for extInterface in opts['externalInterfaces']:
                         if self.checkIntf(extInterface):
                             Intf( extInterface, node=newSwitch )
@@ -2759,13 +2772,13 @@ class MiniEdit( Frame ):
 
                 # Create the correct host class
                 if 'cores' in opts or 'cpu' in opts:
-                    if ('privateDirectory' in opts):
+                    if 'privateDirectory' in opts:
                         hostCls = partial( CPULimitedHost,
                                            privateDirs=opts['privateDirectory'] )
                     else:
                         hostCls=CPULimitedHost
                 else:
-                    if ('privateDirectory' in opts):
+                    if 'privateDirectory' in opts:
                         hostCls = partial( Host,
                                            privateDirs=opts['privateDirectory'] )
                     else:
@@ -2784,11 +2797,11 @@ class MiniEdit( Frame ):
                     newHost.setCPUFrac(f=opts['cpu'], sched=opts['sched'])
 
                 # Attach external interfaces
-                if ('externalInterfaces' in opts):
+                if 'externalInterfaces' in opts:
                     for extInterface in opts['externalInterfaces']:
                         if self.checkIntf(extInterface):
                             Intf( extInterface, node=newHost )
-                if ('vlanInterfaces' in opts):
+                if 'vlanInterfaces' in opts:
                     if len(opts['vlanInterfaces']) > 0:
                         print 'Checking that OS is VLAN prepared'
                         self.pathCheck('vconfig', moduleName='vlan package')
@@ -2894,18 +2907,18 @@ class MiniEdit( Frame ):
                 newHost = self.net.get(name)
                 opts = self.hostOpts[name]
                 # Attach vlan interfaces
-                if ('vlanInterfaces' in opts):
+                if 'vlanInterfaces' in opts:
                     for vlanInterface in opts['vlanInterfaces']:
                         print 'adding vlan interface '+vlanInterface[1]
                         newHost.cmdPrint('ifconfig '+name+'-eth0.'+vlanInterface[1]+' '+vlanInterface[0])
                 # Run User Defined Start Command
-                if ('startCommand' in opts):
+                if 'startCommand' in opts:
                     newHost.cmdPrint(opts['startCommand'])
             if 'Switch' in tags:
                 newNode = self.net.get(name)
                 opts = self.switchOpts[name]
                 # Run User Defined Start Command
-                if ('startCommand' in opts):
+                if 'startCommand' in opts:
                     newNode.cmdPrint(opts['startCommand'])
 
 
@@ -3018,13 +3031,13 @@ class MiniEdit( Frame ):
                     newHost = self.net.get(name)
                     opts = self.hostOpts[name]
                     # Run User Defined Stop Command
-                    if ('stopCommand' in opts):
+                    if 'stopCommand' in opts:
                         newHost.cmdPrint(opts['stopCommand'])
                 if 'Switch' in tags:
                     newNode = self.net.get(name)
                     opts = self.switchOpts[name]
                     # Run User Defined Stop Command
-                    if ('stopCommand' in opts):
+                    if 'stopCommand' in opts:
                         newNode.cmdPrint(opts['stopCommand'])
 
             self.net.stop()
@@ -3033,7 +3046,7 @@ class MiniEdit( Frame ):
 
     def do_linkPopup(self, event):
         # display the popup menu
-        if ( self.net is None ):
+        if self.net is None:
             try:
                 self.linkPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:
@@ -3048,7 +3061,7 @@ class MiniEdit( Frame ):
 
     def do_controllerPopup(self, event):
         # display the popup menu
-        if ( self.net is None ):
+        if self.net is None:
             try:
                 self.controllerPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:
@@ -3057,7 +3070,7 @@ class MiniEdit( Frame ):
 
     def do_legacyRouterPopup(self, event):
         # display the popup menu
-        if ( self.net is not None ):
+        if self.net is not None:
             try:
                 self.legacyRouterRunPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:
@@ -3066,7 +3079,7 @@ class MiniEdit( Frame ):
 
     def do_hostPopup(self, event):
         # display the popup menu
-        if ( self.net is None ):
+        if self.net is None:
             try:
                 self.hostPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:
@@ -3081,7 +3094,7 @@ class MiniEdit( Frame ):
 
     def do_legacySwitchPopup(self, event):
         # display the popup menu
-        if ( self.net is not None ):
+        if self.net is not None:
             try:
                 self.switchRunPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:
@@ -3090,7 +3103,7 @@ class MiniEdit( Frame ):
 
     def do_switchPopup(self, event):
         # display the popup menu
-        if ( self.net is None ):
+        if self.net is None:
             try:
                 self.switchPopup.tk_popup(event.x_root, event.y_root, 0)
             finally:

examples/multilink.py

@@ -11,7 +11,7 @@ from mininet.net import Mininet
 from mininet.topo import Topo
 
 def runMultiLink():
-
+    "Create and run multiple link network"
     topo = simpleMultiLinkTopo( n=2 )
     net = Mininet( topo=topo )
     net.start()
@@ -19,6 +19,7 @@ def runMultiLink():
     net.stop()
 
 class simpleMultiLinkTopo( Topo ):
+    "Simple topology with multiple links"
 
     def __init__( self, n, **kwargs ):
         Topo.__init__( self, **kwargs )

examples/natnet.py

@@ -27,7 +27,7 @@ from mininet.util import irange
 
 class InternetTopo(Topo):
     "Single switch connected to n hosts."
-    def __init__(self, n=2, h=1, **opts):
+    def __init__(self, n=2, **opts):
         Topo.__init__(self, **opts)
 
         # set up inet switch
@@ -67,4 +67,3 @@ def run():
 if __name__ == '__main__':
     setLogLevel('info')
     run()
-

examples/numberedports.py

@@ -20,9 +20,12 @@ def validatePort( switch, intf ):
     else:
         return 1
 
-def net():
+def testPortNumbering():
 
-    "Create a network with 5 hosts."
+    """Test port numbering:
+       Create a network with 5 hosts (using Mininet's
+       mid-level API) and check that implicit and
+       explicit port numbering works as expected."""
 
     net = Mininet( controller=Controller )
 
@@ -45,18 +48,21 @@ def net():
     net.addLink( h2, s1 )
     net.addLink( h3, s1 )
     net.addLink( h4, s1 )
-    net.addLink( h5, s1, port1 = 1, port2 = 9 ) # specify a different port to connect host 5 to on the switch.
+    # specify a different port to connect host 5 to on the switch.
+    net.addLink( h5, s1, port1=1, port2= 9)
 
     info( '*** Starting network\n' )
     net.start()
 
     # print the interfaces and their port numbers
-    info( '\n*** printing and validating the ports running on each interface\n' )
+    info( '\n*** printing and validating the ports '
+          'running on each interface\n' )
     for intfs in s1.intfList():
         if not intfs.name == "lo":
             info( intfs, ': ', s1.ports[intfs],
             '\n' )
-            info ( 'Validating that', intfs, 'is actually on port', s1.ports[intfs], '... ' )
+            info ( 'Validating that', intfs,
+                   'is actually on port', s1.ports[intfs], '... ' )
             if validatePort( s1, intfs ):
                 info( 'Validated.\n' )
     print '\n'
@@ -70,5 +76,4 @@ def net():
 
 if __name__ == '__main__':
     setLogLevel( 'info' )
-    net()
+    testPortNumbering()
-

examples/sshd.py

@@ -81,6 +81,6 @@ if __name__ == '__main__':
     net = TreeNet( depth=1, fanout=4 )
     # get sshd args from the command line or use default args
     # useDNS=no -u0 to avoid reverse DNS lookup timeout
-    opts = ' '.join( sys.argv[ 1: ] ) if len( sys.argv ) > 1 else (
+    argvopts = ' '.join( sys.argv[ 1: ] ) if len( sys.argv ) > 1 else (
         '-D -o UseDNS=no -u0' )
-    sshd( net, opts=opts )
+    sshd( net, opts=argvopts )

examples/vlanhost.py

@@ -35,7 +35,7 @@ class VLANHost( Host ):
         """Configure VLANHost according to (optional) parameters:
            vlan: VLAN ID for default interface"""
 
-        r = super( Host, self ).config( **params )
+        r = super( VLANHost, self ).config( **params )
 
         intf = self.defaultIntf()
         # remove IP from default, "physical" interface

mininet/net.py

@@ -727,9 +727,7 @@ class Mininet( object ):
         if not quietRun( 'which telnet' ):
             error( 'Cannot find telnet in $PATH - required for iperf test' )
             return
-        if not hosts:
+        hosts = hosts or [ self.hosts[ 0 ], self.hosts[ -1 ] ]
-            hosts = [ self.hosts[ 0 ], self.hosts[ -1 ] ]
-        else:
         assert len( hosts ) == 2
         client, server = hosts
         output( '*** Iperf: testing ' + l4Type + ' bandwidth between ' )

mininet/node.py

@@ -888,8 +888,9 @@ class Switch( Node ):
 
     def connected( self ):
         "Is the switch connected to a controller? (override this method)"
-        raise NotImplementedError( "connected() needs to be implemented in"
+        warn( "Warning: connected() needs to be implemented in"
-                                   " Switch subclass %s" % self.__class__ )
+              " Switch subclass %s\n" % self.__class__ )
+        return True
 
     def __repr__( self ):
         "More informative string representation"
@@ -1290,10 +1291,6 @@ class IVSSwitch( Switch ):
         return self.cmd( 'ovs-ofctl ' + ' '.join( args ) +
                          ' tcp:127.0.0.1:%i' % self.listenPort )
 
-    def connected( self ):
-        "For now, return True since we can't tell if we're connected"
-        return True
-
 
 class Controller( Node ):
     """A Controller is a Node that is running (or has execed?) an

mininet/test/runner.py

@@ -26,6 +26,6 @@ def runTests( testDir, verbosity=1 ):
 if __name__ == '__main__':
     setLogLevel( 'warning' )
     # get the directory containing example tests
-    testDir = os.path.dirname( os.path.realpath( __file__ ) )
+    thisdir = os.path.dirname( os.path.realpath( __file__ ) )
-    verbosity = 2 if '-v' in sys.argv else 1
+    vlevel = 2 if '-v' in sys.argv else 1
-    runTests( testDir, verbosity )
+    runTests( testDir=thisdir, verbosity=vlevel )

mininet/test/test_hifi.py

@@ -42,7 +42,8 @@ class testOptionsTopoCommon( object ):
 
     switchClass = None # overridden in subclasses
 
-    def tearDown( self ):
+    @staticmethod
+    def tearDown():
         "Clean up if necessary"
         if sys.exc_info != ( None, None, None ):
             cleanup()
@@ -151,7 +152,7 @@ class testOptionsTopoCommon( object ):
         # As long as the kernel doesn't wait a long time before
         # delivering bytes to the iperf server, its reported data rate
         # should be close to the actual receive rate.
-        serverRate, clientRate = bw_strs
+        serverRate, _clientRate = bw_strs
         bw = float( serverRate.split(' ')[0] )
         self.assertWithinTolerance( bw, BW, BW_TOLERANCE, msg )
 

mininet/test/test_nets.py

@@ -23,7 +23,8 @@ class testSingleSwitchCommon( object ):
 
     switchClass = None # overridden in subclasses
 
-    def tearDown( self ):
+    @staticmethod
+    def tearDown():
         "Clean up if necessary"
         if sys.exc_info != ( None, None, None ):
             cleanup()
@@ -74,7 +75,8 @@ class testLinearCommon( object ):
 
     def testLinear5( self ):
         "Ping test on a 5-switch topology"
-        mn = Mininet( LinearTopo( k=5 ), self.switchClass, Host, Controller, waitConnected=True )
+        mn = Mininet( LinearTopo( k=5 ), self.switchClass, Host,
+                      Controller, waitConnected=True )
         dropped = mn.run( mn.ping )
         self.assertEqual( dropped, 0 )
 

mininet/test/test_walkthrough.py

@@ -19,6 +19,9 @@ def tsharkVersion():
     versionMatch = re.findall( r'TShark \d+.\d+.\d+', versionStr )[0]
     return versionMatch.split()[ 1 ]
 
+# pylint doesn't understand pexpect.match, unfortunately!
+# pylint:disable=maybe-no-member
+
 class testWalkthrough( unittest.TestCase ):
     "Test Mininet walkthrough"
 
@@ -33,7 +36,7 @@ class testWalkthrough( unittest.TestCase ):
 
     def testWireshark( self ):
         "Use tshark to test the of dissector"
-        # Satisfy pylint:
+        # Satisfy pylint
         assert self
         if StrictVersion( tsharkVersion() ) < StrictVersion( '1.12.0' ):
             tshark = pexpect.spawn( 'tshark -i lo -R of' )
@@ -78,7 +81,8 @@ class testWalkthrough( unittest.TestCase ):
             node = p.match.group( 1 )
             actual.append( node )
             p.expect( '\n' )
-        self.assertEqual( actual.sort(), nodes.sort(), '"nodes" and "dump" differ' )
+        self.assertEqual( actual.sort(), nodes.sort(),
+                          '"nodes" and "dump" differ' )
         p.expect( self.prompt )
         p.sendline( 'exit' )
         p.wait()
@@ -202,7 +206,8 @@ class testWalkthrough( unittest.TestCase ):
         p.expect( self.prompt )
         # test delay
         p.sendline( 'h1 ping -c 4 h2' )
-        p.expect( r'rtt min/avg/max/mdev = ([\d\.]+)/([\d\.]+)/([\d\.]+)/([\d\.]+) ms' )
+        p.expect( r'rtt min/avg/max/mdev = '
+                  r'([\d\.]+)/([\d\.]+)/([\d\.]+)/([\d\.]+) ms' )
         delay = float( p.match.group( 2 ) )
         self.assertTrue( delay > 40, 'Delay < 40ms' )
         self.assertTrue( delay < 45, 'Delay > 40ms' )
@@ -226,10 +231,13 @@ class testWalkthrough( unittest.TestCase ):
 
     def testCustomTopo( self ):
         "Start Mininet using a custom topo, then run pingall"
+        # Satisfy pylint
+        assert self
         custom = os.path.dirname( os.path.realpath( __file__ ) )
         custom = os.path.join( custom, '../../custom/topo-2sw-2host.py' )
         custom = os.path.normpath( custom )
-        p = pexpect.spawn( 'mn --custom %s --topo mytopo --test pingall' % custom )
+        p = pexpect.spawn(
+            'mn --custom %s --topo mytopo --test pingall' % custom )
         p.expect( '0% dropped' )
         p.expect( pexpect.EOF )
 
@@ -331,11 +339,15 @@ class testWalkthrough( unittest.TestCase ):
                           'Github is not reachable; cannot download Pox' )
     def testRemoteController( self ):
         "Test Mininet using Pox controller"
+        # Satisfy pylint
+        assert self
         if not os.path.exists( '/tmp/pox' ):
-            p = pexpect.spawn( 'git clone https://github.com/noxrepo/pox.git /tmp/pox' )
+            p = pexpect.spawn(
+                'git clone https://github.com/noxrepo/pox.git /tmp/pox' )
             p.expect( pexpect.EOF )
         pox = pexpect.spawn( '/tmp/pox/pox.py forwarding.l2_learning' )
-        net = pexpect.spawn( 'mn --controller=remote,ip=127.0.0.1,port=6633 --test pingall' )
+        net = pexpect.spawn(
+            'mn --controller=remote,ip=127.0.0.1,port=6633 --test pingall' )
         net.expect( '0% dropped' )
         net.expect( pexpect.EOF )
         pox.sendintr()

mininet/util.py

@@ -427,6 +427,7 @@ def fixLimits():
         sysctlTestAndSet( 'net.ipv4.route.max_size', 32768 )
         #Increase number of PTYs for nodes
         sysctlTestAndSet( 'kernel.pty.max', 20000 )
+    # pylint: disable=broad-except
     except Exception:
         warn( "*** Error setting resource limits. "
               "Mininet's performance may be affected.\n" )
@@ -549,6 +550,7 @@ def waitListening( client=None, server='127.0.0.1', port=80, timeout=None ):
                 partial( quietRun, shell=True ) )
     if not runCmd( 'which telnet' ):
         raise Exception('Could not find telnet' )
+    # pylint: disable=maybe-no-member
     serverIP = server if isinstance( server, basestring ) else server.IP()
     cmd = ( 'sh -c "echo A | telnet -e A %s %s"' %
            ( serverIP, port ) )