Pass code check with pylint=2.4.4 (#1012)

.github/workflows/code-check.yaml

@@ -0,0 +1,22 @@
+
+name: code-check
+
+on: [push, pull_request]
+
+jobs:
+  code-check:
+    name: Mininet Code Check
+    runs-on: ubuntu-latest
+    steps:
+      - name: Set up Python 3.x
+        uses: actions/setup-python@v2
+        with:
+          python-version: 3.x
+      - name: Check out Mininet source
+        uses: actions/checkout@v2
+      - name: Install Mininet code check dependencies
+        run: |
+          PYTHON=`which python` util/install.sh -n
+          python -m pip install pylint==2.4.4
+      - name: Run code check
+        run:  make codecheck

.github/workflows/run-tests.yaml

@@ -24,9 +24,6 @@ jobs:
           # This seems too slow unfortunately:
           # sudo apt-get upgrade -y -qq
           PYTHON=`which python` util/install.sh -nv
-      - name: Run code check (skipping for now)
-        run: |
-          bash -c "if [ `lsb_release -rs` == '14.04' ]; then make codecheck; fi"
       - name: Sanity test
         run: |
           export sudo="sudo env PATH=$PATH"

.pylint

@@ -41,10 +41,16 @@ load-plugins=
 # can either give multiple identifier separated by comma (,) or put this option
 # multiple time (only on the command line, not in the configuration file where
 # it should appear only once).
+#
+# Note: we may want to re-enable some of these at some point, but many of them
+# are just style issues rather than errors.
+#
 disable=pointless-except, invalid-name, super-init-not-called, fixme, star-args,
-        too-many-instance-attributes, too-few-public-methods, too-many-arguments,
+        too-many-instance-attributes, too-few-public-methods,
         too-many-locals, too-many-public-methods, duplicate-code, bad-whitespace,
-        locally-disabled, locally-enabled
+        locally-disabled, locally-enabled, bad-continuation,
+        useless-object-inheritance, unnecessary-pass, no-else-return,
+        no-else-raise, no-else-continue, super-with-arguments
 
 # bad-continuation, wrong-import-order
 

.travis.yml

@@ -3,20 +3,17 @@ sudo: required
 
 matrix:
   include:
-    - dist: trusty
+    - dist: focal
-      python: 2.7
-      env: dist="14.04 LTS trusty"
-    - dist: trusty
       python: 3.6
-      env: dist="14.04 LTS trusty"
+      env: dist="24.04 LTS focal"
 
 before_install:
 - sudo apt-get update -qq
-- sudo apt-get install -qq vlan
+- sudo apt-get install -qq vlan pyflakes
 - PYTHON=`which python` util/install.sh -n
 
 install:
-- bash -c "if [ `lsb_release -rs` == '14.04' ]; then make codecheck; fi"
+- make codecheck
 - pip install pexpect || pip3 install pexpect
 - util/install.sh -nfvw
 

Makefile

@@ -8,7 +8,7 @@ BIN = $(MN)
 PYSRC = $(MININET) $(TEST) $(EXAMPLES) $(BIN)
 MNEXEC = mnexec
 MANPAGES = mn.1 mnexec.1
-P8IGN = E251,E201,E302,E202,E126,E127,E203,E226
+P8IGN = E251,E201,E302,E202,E126,E127,E203,E226,E402,W504,W503,E731
 PREFIX ?= /usr
 BINDIR ?= $(PREFIX)/bin
 MANDIR ?= $(PREFIX)/share/man/man1

bin/mn

@@ -11,15 +11,20 @@ Example to pull custom params (topo, switch, etc.) from a file:
   sudo mn --custom ~/mininet/custom/custom_example.py
 """
 
-from optparse import OptionParser
 import os
 import sys
 import time
 
+from functools import partial
+from optparse import OptionParser  # pylint: disable=deprecated-module
+from sys import exit  # pylint: disable=redefined-builtin
+
 # Fix setuptools' evil madness, and open up (more?) security holes
 if 'PYTHONPATH' in os.environ:
     sys.path = os.environ[ 'PYTHONPATH' ].split( ':' ) + sys.path
 
+# pylint: disable=wrong-import-position
+
 from mininet.clean import cleanup
 import mininet.cli
 from mininet.log import lg, LEVELS, info, debug, warn, error, output
@@ -34,10 +39,7 @@ from mininet.link import Link, TCLink, TCULink, OVSLink
 from mininet.topo import ( SingleSwitchTopo, LinearTopo,
                            SingleSwitchReversedTopo, MinimalTopo )
 from mininet.topolib import TreeTopo, TorusTopo
-from mininet.util import customClass, specialClass, splitArgs
+from mininet.util import customClass, specialClass, splitArgs, buildTopo
-from mininet.util import buildTopo
-
-from functools import partial
 
 # Experimental! cluster edition prototype
 from mininet.examples.cluster import ( MininetCluster, RemoteHost,
@@ -46,6 +48,7 @@ from mininet.examples.cluster import ( MininetCluster, RemoteHost,
                                        ClusterCleanup )
 from mininet.examples.clustercli import ClusterCLI
 
+
 PLACEMENT = { 'block': SwitchBinPlacer, 'random': RandomPlacer }
 
 # built in topologies, created only when run
@@ -107,6 +110,7 @@ def nullTest( _net ):
     "Null 'test' (does nothing)"
     pass
 
+
 TESTS.update( all=allTest, none=nullTest, build=nullTest )
 
 # Map to alternate spellings of Mininet() methods
@@ -425,7 +429,7 @@ if __name__ == "__main__":
     except KeyboardInterrupt:
         info( "\n\nKeyboard Interrupt. Shutting down and cleaning up...\n\n")
         cleanup()
-    except Exception:
+    except Exception:  # pylint: disable=broad-except
         # Print exception
         type_, val_, trace_ = sys.exc_info()
         errorMsg = ( "-"*80 + "\n" +

examples/bind.py

@@ -34,14 +34,14 @@ and '/var/run'. It also has a temporary private directory mounted
 on '/var/mn'
 """
 
+from functools import partial
+
 from mininet.net import Mininet
 from mininet.node import Host
 from mininet.cli import CLI
 from mininet.topo import SingleSwitchTopo
 from mininet.log import setLogLevel, info
 
-from functools import partial
-
 
 # Sample usage
 
@@ -61,6 +61,7 @@ def testHostWithPrivateDirs():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     testHostWithPrivateDirs()

examples/cluster.py

@@ -74,6 +74,15 @@ Things to do:
 - hifi support (e.g. delay compensation)
 """
 
+from signal import signal, SIGINT, SIG_IGN
+from subprocess import Popen, PIPE, STDOUT
+import os
+from random import randrange
+import sys
+import re
+from itertools import groupby
+from operator import attrgetter
+from distutils.version import StrictVersion
 
 from mininet.node import Node, Host, OVSSwitch, Controller
 from mininet.link import Link, Intf
@@ -85,15 +94,7 @@ from mininet.examples.clustercli import CLI
 from mininet.log import setLogLevel, debug, info, error
 from mininet.clean import addCleanupCallback
 
-from signal import signal, SIGINT, SIG_IGN
+# pylint: disable=too-many-arguments
-from subprocess import Popen, PIPE, STDOUT
-import os
-from random import randrange
-import sys
-import re
-from itertools import groupby
-from operator import attrgetter
-from distutils.version import StrictVersion
 
 
 def findUser():
@@ -261,7 +262,7 @@ class RemoteMixin( object ):
             cmd: remote command to run (list)
             **params: parameters to Popen()
             returns: Popen() object"""
-        if type( cmd ) is str:
+        if isinstance( cmd, str):
             cmd = cmd.split()
         if self.isRemote:
             if sudo:
@@ -289,6 +290,7 @@ class RemoteMixin( object ):
     def addIntf( self, *args, **kwargs ):
         "Override: use RemoteLink.moveIntf"
         # kwargs.update( moveIntfFn=RemoteLink.moveIntf )
+        # pylint: disable=useless-super-delegation
         return super( RemoteMixin, self).addIntf( *args, **kwargs )
 
 
@@ -325,6 +327,7 @@ class RemoteOVSSwitch( RemoteMixin, OVSSwitch ):
                  StrictVersion( '1.10' ) )
 
     @classmethod
+    # pylint: disable=arguments-differ
     def batchStartup( cls, switches, **_kwargs ):
         "Start up switches in per-server batches"
         key = attrgetter( 'server' )
@@ -336,6 +339,7 @@ class RemoteOVSSwitch( RemoteMixin, OVSSwitch ):
         return switches
 
     @classmethod
+    # pylint: disable=arguments-differ
     def batchShutdown( cls, switches, **_kwargs ):
         "Stop switches in per-server batches"
         key = attrgetter( 'server' )
@@ -413,8 +417,9 @@ class RemoteLink( Link ):
         # And we can't ssh into this server remotely as 'localhost',
         # so try again swappping node1 and node2
         if node2.server == 'localhost':
-            return self.makeTunnel( node2, node1, intfname2, intfname1,
+            return self.makeTunnel( node1=node2, node2=node1,
-                                    addr2, addr1 )
+                                    intfname1=intfname2, intfname2=intfname1,
+                                    addr1=addr2, addr2=addr1 )
         debug( '\n*** Make SSH tunnel ' + node1.server + ':' + intfname1 +
                ' == ' + node2.server + ':' + intfname2 )
         # 1. Create tap interfaces
@@ -526,8 +531,9 @@ class RemoteGRELink( RemoteLink ):
         # We should never try to create a tunnel to ourselves!
         assert node1.server != node2.server
         if node2.server == 'localhost':
-            return self.makeTunnel( node2, node1, intfname2, intfname1,
+            return self.makeTunnel( node1=node2, node2=node1,
-                                    addr2, addr1 )
+                                    intfname1=intfname2, intfname2=intfname1,
+                                    addr1=addr2, addr2=addr1 )
         IP1, IP2 = node1.serverIP, node2.serverIP
         # GRE tunnel needs to be set up with the IP of the local interface
         # that connects the remote node, NOT '127.0.0.1' of localhost
@@ -555,6 +561,7 @@ class RemoteGRELink( RemoteLink ):
             node.rcmd('ip link set dev %s mtu 1450' % intfname)
             if not self.moveIntf(intfname, node):
                 raise Exception('interface move failed on node %s' % node)
+        return None  # May want to return something useful here
 
 
 # Some simple placement algorithms for MininetCluster
@@ -589,10 +596,10 @@ class Placer( object ):
 
 class RandomPlacer( Placer ):
     "Random placement"
-    def place( self, nodename ):
+    def place( self, node ):
         """Random placement function
-            nodename: node name"""
+            node: node"""
-        assert nodename  # please pylint
+        assert node  # please pylint
         # This may be slow with lots of servers
         return self.servers[ randrange( 0, len( self.servers ) ) ]
 
@@ -606,10 +613,10 @@ class RoundRobinPlacer( Placer ):
         Placer.__init__( self, *args, **kwargs )
         self.next = 0
 
-    def place( self, nodename ):
+    def place( self, node ):
         """Round-robin placement function
-            nodename: node name"""
+            node: node"""
-        assert nodename  # please pylint
+        assert node  # please pylint
         # This may be slow with lots of servers
         server = self.servers[ self.next ]
         self.next = ( self.next + 1 ) % len( self.servers )
@@ -647,7 +654,7 @@ class SwitchBinPlacer( Placer ):
         tickets = sum( [ binsizes[ server ] * [ server ]
                          for server in servers ], [] )
         # And assign one ticket to each node
-        return { node: ticket for node, ticket in zip( nodes, tickets ) }
+        return dict( zip( nodes, tickets ) )
 
     def calculatePlacement( self ):
         "Pre-calculate node placement"
@@ -704,21 +711,21 @@ class HostSwitchBinPlacer( Placer ):
         self.cset = frozenset( self.controllers )
         self.hind, self.sind, self.cind = 0, 0, 0
 
-    def place( self, nodename ):
+    def place( self, node ):
         """Simple placement algorithm:
             place nodes into evenly sized bins"""
         # Place nodes into bins
-        if nodename in self.hset:
+        if node in self.hset:
             server = self.servdict[ self.hind / self.hbin ]
             self.hind += 1
-        elif nodename in self.sset:
+        elif node in self.sset:
             server = self.servdict[ self.sind / self.sbin ]
             self.sind += 1
-        elif nodename in self.cset:
+        elif node in self.cset:
             server = self.servdict[ self.cind / self.cbin ]
             self.cind += 1
         else:
-            info( 'warning: unknown node', nodename )
+            info( 'warning: unknown node', node )
             server = self.servdict[ 0 ]
         return server
 
@@ -764,6 +771,7 @@ class MininetCluster( Mininet ):
         # Make sure control directory exists
         self.cdir = os.environ[ 'HOME' ] + '/.ssh/mn'
         errRun( [ 'mkdir', '-p', self.cdir ] )
+        # pylint: disable=unexpected-keyword-arg
         Mininet.__init__( self, *args, **params )
 
     def popen( self, cmd ):
@@ -840,18 +848,19 @@ class MininetCluster( Mininet ):
             if cfile:
                 config.setdefault( 'controlPath', cfile )
 
+    # pylint: disable=arguments-differ,signature-differs
     def addController( self, *args, **kwargs ):
         "Patch to update IP address to global IP address"
         controller = Mininet.addController( self, *args, **kwargs )
         loopback = '127.0.0.1'
         if ( not isinstance( controller, Controller ) or
              controller.IP() != loopback ):
-            return
+            return None
         # Find route to a different server IP address
         serverIPs = [ ip for ip in self.serverIP.values()
                       if ip is not controller.IP() ]
         if not serverIPs:
-            return  # no remote servers - loopback is fine
+            return None  # no remote servers - loopback is fine
         remoteIP = serverIPs[ 0 ]
         # Route should contain 'dev <intfname>'
         route = controller.cmd( 'ip route get', remoteIP,
@@ -865,6 +874,7 @@ class MininetCluster( Mininet ):
         debug( controller, 'IP address updated to', controller.IP() )
         return controller
 
+    # pylint: disable=arguments-differ,signature-differs
     def buildFromTopo( self, *args, **kwargs ):
         "Start network"
         info( '*** Placing nodes\n' )

examples/clusterSanity.py

@@ -17,6 +17,7 @@ def clusterSanity():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     clusterSanity()

examples/clustercli.py

@@ -31,6 +31,7 @@ class ClusterCLI( CLI ):
         if not nx:
             try:
                 # pylint: disable=import-error,no-member
+                # pylint: disable=import-outside-toplevel
                 import networkx
                 nx = networkx  # satisfy pylint
                 from matplotlib import pyplot

examples/clusterdemo.py

@@ -19,6 +19,7 @@ def demo():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     demo()

examples/clusterperf.py

@@ -17,6 +17,7 @@ def perf(Link):
     net.iperf()
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel('info')
     perf( RemoteSSHLink )

examples/consoles.py

@@ -27,6 +27,7 @@ Bob Lantz, April 2010
 
 import re
 
+# pylint: disable=import-error
 from Tkinter import Frame, Button, Label, Text, Scrollbar, Canvas, Wm, READABLE
 
 from mininet.log import setLogLevel
@@ -34,6 +35,9 @@ from mininet.topolib import TreeNet
 from mininet.term import makeTerms, cleanUpScreens
 from mininet.util import quietRun
 
+# pylint: disable=too-many-arguments
+
+
 class Console( Frame ):
     "A simple console on a host."
 
@@ -319,7 +323,7 @@ class ConsoleApp( Frame ):
         if not m:
             return
         val, units = float( m.group( 1 ) ), m.group( 2 )
-        #convert to Gbps
+        # convert to Gbps
         if units[0] == 'M':
             val *= 10 ** -3
         elif units[0] == 'K':

examples/controllers.py

@@ -26,6 +26,7 @@ class MultiSwitch( OVSSwitch ):
     def start( self, controllers ):
         return OVSSwitch.start( self, [ cmap[ self.name ] ] )
 
+
 topo = TreeTopo( depth=2, fanout=2 )
 net = Mininet( topo=topo, switch=MultiSwitch, build=False, waitConnected=True )
 for c in [ c0, c1 ]:

examples/controllers2.py

@@ -58,6 +58,7 @@ def multiControllerNet():
     info( "*** Stopping network\n" )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )  # for CLI output
     multiControllerNet()

examples/controlnet.py

@@ -59,13 +59,14 @@ class MininetFacade( object ):
 
     def __getitem__( self, key ):
         "returns primary/named networks or node from any net"
-        #search kwargs for net named key
+        # search kwargs for net named key
         if key in self.nameToNet:
             return self.nameToNet[ key ]
-        #search each net for node named key
+        # search each net for node named key
         for net in self.nets:
             if key in net:
                 return net[ key ]
+        return None
 
     def __iter__( self ):
         "Iterate through all nodes in all Mininet objects"
@@ -100,6 +101,7 @@ class MininetFacade( object ):
 
 class ControlNetwork( Topo ):
     "Control Network Topology"
+    # pylint: disable=arguments-differ
     def build( self, n, dataController=DataController, **_kwargs ):
         """n: number of data network controller nodes
            dataController: class for data network controllers"""

examples/cpu.py

@@ -54,7 +54,7 @@ def bwtest( cpuLimits, period_us=100000, seconds=10 ):
             try:
                 net = Mininet( topo=topo, host=host, waitConnected=True )
             # pylint: disable=bare-except
-            except:
+            except:  # noqa
                 info( '*** Skipping scheduler %s and cleaning up\n' % sched )
                 cleanup()
                 break

examples/emptynet.py

@@ -39,6 +39,7 @@ def emptyNet():
     info( '*** Stopping network' )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     emptyNet()

examples/hwintf.py

@@ -8,6 +8,8 @@ hardware interface) to a network after the network is created.
 import re
 import sys
 
+from sys import exit  # pylint: disable=redefined-builtin
+
 from mininet.cli import CLI
 from mininet.log import setLogLevel, info, error
 from mininet.net import Mininet
@@ -15,6 +17,7 @@ from mininet.link import Intf
 from mininet.topolib import TreeTopo
 from mininet.util import quietRun
 
+
 def checkIntf( intf ):
     "Make sure intf exists and is not configured."
     config = quietRun( 'ifconfig %s 2>/dev/null' % intf, shell=True )
@@ -27,6 +30,7 @@ def checkIntf( intf ):
                'and is probably in use!\n' )
         exit( 1 )
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
 

examples/intfoptions.py

@@ -43,6 +43,7 @@ def intfOptions():
     info( '\n*** Done testing\n' )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     intfOptions()

examples/limit.py

@@ -55,6 +55,7 @@ def verySimpleLimit( bw=150 ):
     h2.cmdPrint( 'tc -d class show dev', h2.defaultIntf() )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     limit()

examples/linearbandwidth.py

@@ -24,20 +24,24 @@ of switches, this example demonstrates:
 """
 
 
+import sys
+
+from functools import partial
+
 from mininet.net import Mininet
 from mininet.node import UserSwitch, OVSKernelSwitch, Controller
 from mininet.topo import Topo
 from mininet.log import lg, info
 from mininet.util import irange, quietRun
 from mininet.link import TCLink
-from functools import partial
 
-import sys
 flush = sys.stdout.flush
 
+
 class LinearTestTopo( Topo ):
     "Topology for a string of N hosts and N-1 switches."
 
+    # pylint: disable=arguments-differ
     def build( self, N, **params ):
         # Create switches and hosts
         hosts = [ self.addHost( 'h%s' % h )
@@ -79,7 +83,7 @@ def linearBandwidthTest( lengths ):
     output = quietRun( 'sysctl -w net.ipv4.tcp_congestion_control=reno' )
     assert 'reno' in output
 
-    for datapath in switches.keys():
+    for datapath in switches:
         info( "*** testing", datapath, "datapath\n" )
         Switch = switches[ datapath ]
         results[ datapath ] = []
@@ -105,7 +109,7 @@ def linearBandwidthTest( lengths ):
             results[ datapath ] += [ ( n, serverbw ) ]
         net.stop()
 
-    for datapath in switches.keys():
+    for datapath in switches:
         info( "\n*** Linear network results for", datapath, "datapath:\n" )
         result = results[ datapath ]
         info( "SwitchCount\tiperf Results\n" )
@@ -115,6 +119,7 @@ def linearBandwidthTest( lengths ):
         info( '\n')
     info( '\n' )
 
+
 if __name__ == '__main__':
     lg.setLogLevel( 'info' )
     sizes = [ 1, 2, 3, 4 ]

examples/linuxrouter.py

@@ -38,6 +38,7 @@ from mininet.cli import CLI
 class LinuxRouter( Node ):
     "A Node with IP forwarding enabled."
 
+    # pylint: disable=arguments-differ
     def config( self, **params ):
         super( LinuxRouter, self).config( **params )
         # Enable forwarding on the router
@@ -51,6 +52,7 @@ class LinuxRouter( Node ):
 class NetworkTopo( Topo ):
     "A LinuxRouter connecting three IP subnets"
 
+    # pylint: disable=arguments-differ
     def build( self, **_opts ):
 
         defaultIP = '192.168.1.1/24'  # IP address for r0-eth1
@@ -87,6 +89,7 @@ def run():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     run()

examples/miniedit.py

@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 """
 MiniEdit: a simple network editor for Mininet
@@ -13,16 +13,30 @@ Controller icon from http://semlabs.co.uk/
 OpenFlow icon from https://www.opennetworking.org/
 """
 
-# Miniedit needs some work in order to pass pylint...
+import json
-# pylint: disable=line-too-long,too-many-branches
+import os
-# pylint: disable=too-many-statements,attribute-defined-outside-init
+import re
-# pylint: disable=missing-docstring
-
-MINIEDIT_VERSION = '2.2.0.1'
-
 import sys
+
+from distutils.version import StrictVersion
+from functools import partial
 from optparse import OptionParser
 from subprocess import call
+from sys import exit  # pylint: disable=redefined-builtin
+
+from mininet.log import info, debug, warn, setLogLevel
+from mininet.net import Mininet, VERSION
+from mininet.util import (netParse, ipAdd, quietRun,
+                          buildTopo, custom, customClass )
+from mininet.term import makeTerm, cleanUpScreens
+from mininet.node import (Controller, RemoteController, NOX, OVSController,
+                          CPULimitedHost, Host, Node,
+                          OVSSwitch, UserSwitch, IVSSwitch )
+from mininet.link import TCLink, Intf, Link
+from mininet.cli import CLI
+from mininet.moduledeps import moduleDeps
+from mininet.topo import SingleSwitchTopo, LinearTopo, SingleSwitchReversedTopo
+from mininet.topolib import TreeTopo
 
 # pylint: disable=import-error
 if sys.version_info[0] == 2:
@@ -47,38 +61,24 @@ else:
     from tkinter import font as tkFont
     from tkinter import simpledialog as tkSimpleDialog
     from tkinter import filedialog as tkFileDialog
+# someday: from ttk import *
 # pylint: enable=import-error
 
-import re
+
-import json
+# Miniedit still needs work in order to pass pylint...
-from distutils.version import StrictVersion
+# pylint: disable=line-too-long,too-many-branches
-import os
+# pylint: disable=too-many-statements,attribute-defined-outside-init
-from functools import partial
+# pylint: disable=missing-docstring,too-many-ancestors
+# pylint: disable=too-many-nested-blocks,too-many-arguments
+
+
+MINIEDIT_VERSION = '2.2.0.1'
 
 if 'PYTHONPATH' in os.environ:
     sys.path = os.environ[ 'PYTHONPATH' ].split( ':' ) + sys.path
 
-# someday: from ttk import *
-
-from mininet.log import info, debug, warn, setLogLevel
-from mininet.net import Mininet, VERSION
-from mininet.util import netParse, ipAdd, quietRun
-from mininet.util import buildTopo
-from mininet.util import custom, customClass
-from mininet.term import makeTerm, cleanUpScreens
-from mininet.node import Controller, RemoteController, NOX, OVSController
-from mininet.node import CPULimitedHost, Host, Node
-from mininet.node import OVSSwitch, UserSwitch
-from mininet.link import TCLink, Intf, Link
-from mininet.cli import CLI
-from mininet.moduledeps import moduleDeps
-from mininet.topo import SingleSwitchTopo, LinearTopo, SingleSwitchReversedTopo
-from mininet.topolib import TreeTopo
-
 info( 'MiniEdit running against Mininet '+VERSION, '\n' )
 MININET_VERSION = re.sub(r'[^\d\.]', '', VERSION)
-if StrictVersion(MININET_VERSION) > StrictVersion('2.0'):
-    from mininet.node import IVSSwitch
 
 TOPODEF = 'none'
 TOPOS = { 'minimal': lambda: SingleSwitchTopo( k=2 ),
@@ -138,6 +138,7 @@ class LegacyRouter( Node ):
     def __init__( self, name, inNamespace=True, **params ):
         Node.__init__( self, name, inNamespace, **params )
 
+    # pylint: disable=arguments-differ
     def config( self, **_params ):
         if self.intfs:
             self.setParam( _params, 'setIP', ip='0.0.0.0' )
@@ -818,8 +819,8 @@ class VerticalScrolledTable(LabelFrame):
     * This frame only allows vertical scrolling
 
     """
-    def __init__(self, parent, rows=2, columns=2, title=None, *args, **kw):
+    def __init__(self, parent, rows=2, columns=2, title=None, **kw):
-        LabelFrame.__init__(self, parent, text=title, padx=5, pady=5, *args, **kw)
+        LabelFrame.__init__(self, parent, text=title, padx=5, pady=5, **kw)
 
         # create a canvas object and a vertical scrollbar for scrolling it
         vscrollbar = Scrollbar(self, orient=VERTICAL)
@@ -855,8 +856,6 @@ class VerticalScrolledTable(LabelFrame):
                 canvas.itemconfigure(interior_id, width=canvas.winfo_width())
         canvas.bind('<Configure>', _configure_canvas)
 
-        return
-
 class TableFrame(Frame):
     def __init__(self, parent, rows=2, columns=2):
 
@@ -888,7 +887,7 @@ 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:
                 label.configure(state='readonly')
             current_row.append(label)
         self._widgets.append(current_row)
@@ -1401,11 +1400,11 @@ class MiniEdit( Frame ):
 
     def addNode( self, node, nodeNum, x, y, name=None):
         "Add a new node to our canvas."
-        if 'Switch' == node:
+        if node == 'Switch':
             self.switchCount += 1
-        if 'Host' == node:
+        if node == 'Host':
             self.hostCount += 1
-        if 'Controller' == node:
+        if node == 'Controller':
             self.controllerCount += 1
         if name is None:
             name = self.nodePrefixes[ node ] + nodeNum
@@ -1422,13 +1421,16 @@ class MiniEdit( Frame ):
 
     def convertJsonUnicode(self, text):
         "Some part of Mininet don't like Unicode"
+        try:
+            unicode
+        except NameError:
+            return text
         if isinstance(text, dict):
             return {self.convertJsonUnicode(key): self.convertJsonUnicode(value) for key, value in text.items()}
-        elif isinstance(text, list):
+        if isinstance(text, list):
             return [self.convertJsonUnicode(element) for element in text]
-        elif isinstance(text, unicode):
+        if isinstance(text, unicode):  # pylint: disable=undefined-variable
             return text.encode('utf-8')
-        else:
         return text
 
     def loadTopology( self ):
@@ -1440,7 +1442,7 @@ class MiniEdit( Frame ):
             ('All Files','*'),
         ]
         f = tkFileDialog.askopenfile(filetypes=myFormats, mode='rb')
-        if f == None:
+        if f is None:
             return
         self.newTopology()
         loadedTopology = self.convertJsonUnicode(json.load(f))
@@ -1601,10 +1603,11 @@ class MiniEdit( Frame ):
         for widget in self.widgetToItem:
             if name ==  widget[ 'text' ]:
                 return widget
+        return None
 
     def newTopology( self ):
         "New command."
-        for widget in self.widgetToItem.keys():
+        for widget in self.widgetToItem:
             self.deleteItem( self.widgetToItem[ widget ] )
         self.hostCount = 0
         self.switchCount = 0
@@ -1725,7 +1728,7 @@ class MiniEdit( Frame ):
                     if controllerType == 'inband':
                         inBandCtrl = True
 
-            if inBandCtrl == True:
+            if inBandCtrl:
                 f.write("\n")
                 f.write("class InbandController( RemoteController ):\n")
                 f.write("\n")
@@ -2122,7 +2125,7 @@ class MiniEdit( Frame ):
         c = self.canvas
         x, y = c.canvasx( event.x ), c.canvasy( event.y )
         name = self.nodePrefixes[ node ]
-        if 'Switch' == node:
+        if node == 'Switch':
             self.switchCount += 1
             name = self.nodePrefixes[ node ] + str( self.switchCount )
             self.switchOpts[name] = {}
@@ -2130,14 +2133,14 @@ class MiniEdit( Frame ):
             self.switchOpts[name]['hostname']=name
             self.switchOpts[name]['switchType']='default'
             self.switchOpts[name]['controllers']=[]
-        if 'LegacyRouter' == node:
+        if node == 'LegacyRouter':
             self.switchCount += 1
             name = self.nodePrefixes[ node ] + str( self.switchCount )
             self.switchOpts[name] = {}
             self.switchOpts[name]['nodeNum']=self.switchCount
             self.switchOpts[name]['hostname']=name
             self.switchOpts[name]['switchType']='legacyRouter'
-        if 'LegacySwitch' == node:
+        if node == 'LegacySwitch':
             self.switchCount += 1
             name = self.nodePrefixes[ node ] + str( self.switchCount )
             self.switchOpts[name] = {}
@@ -2145,13 +2148,13 @@ class MiniEdit( Frame ):
             self.switchOpts[name]['hostname']=name
             self.switchOpts[name]['switchType']='legacySwitch'
             self.switchOpts[name]['controllers']=[]
-        if 'Host' == node:
+        if node == 'Host':
             self.hostCount += 1
             name = self.nodePrefixes[ node ] + str( self.hostCount )
             self.hostOpts[name] = {'sched':'host'}
             self.hostOpts[name]['nodeNum']=self.hostCount
             self.hostOpts[name]['hostname']=name
-        if 'Controller' == node:
+        if node == 'Controller':
             name = self.nodePrefixes[ node ] + str( self.controllerCount )
             ctrlr = { 'controllerType': 'ref',
                       'hostname': name,
@@ -2169,15 +2172,15 @@ class MiniEdit( Frame ):
         self.itemToWidget[ item ] = icon
         self.selectItem( item )
         icon.links = {}
-        if 'Switch' == node:
+        if node == 'Switch':
             icon.bind('<Button-3>', self.do_switchPopup )
-        if 'LegacyRouter' == node:
+        if node == 'LegacyRouter':
             icon.bind('<Button-3>', self.do_legacyRouterPopup )
-        if 'LegacySwitch' == node:
+        if node == 'LegacySwitch':
             icon.bind('<Button-3>', self.do_legacySwitchPopup )
-        if 'Host' == node:
+        if node == 'Host':
             icon.bind('<Button-3>', self.do_hostPopup )
-        if 'Controller' == node:
+        if node == 'Controller':
             icon.bind('<Button-3>', self.do_controllerPopup )
 
     def clickController( self, event ):
@@ -2374,6 +2377,8 @@ class MiniEdit( Frame ):
         # For now, don't allow hosts to be directly linked
         stags = self.canvas.gettags( self.widgetToItem[ source ] )
         dtags = self.canvas.gettags( target )
+        # TODO: Make this less confusing
+        # pylint: disable=too-many-boolean-expressions
         if (('Host' in stags and 'Host' in dtags) or
            ('Controller' in dtags and 'LegacyRouter' in stags) or
            ('Controller' in stags and 'LegacyRouter' in dtags) or
@@ -2657,7 +2662,7 @@ class MiniEdit( Frame ):
             linkopts = {}
         source.links[ dest ] = self.link
         dest.links[ source ] = self.link
-        self.links[ self.link ] = {'type' :linktype,
+        self.links[ self.link ] = {'type':linktype,
                                    'src':source,
                                    'dest':dest,
                                    'linkOpts':linkopts}
@@ -3225,7 +3230,8 @@ class MiniEdit( Frame ):
         "Parse custom file and add params before parsing cmd-line options."
         customs = {}
         if os.path.isfile( fileName ):
-            execfile( fileName, customs, customs )
+            with open( fileName, 'r' ) as f:
+                exec( f.read() )  # pylint: disable=exec-used
             for name, val in customs.items():
                 self.setCustom( name, val )
         else:
@@ -3592,8 +3598,7 @@ def addDictOption( opts, choicesDict, default, name, helpStr=None ):
 if __name__ == '__main__':
     setLogLevel( 'info' )
     app = MiniEdit()
-    ### import topology if specified ###
     app.parseArgs()
+    ### import topology if specified ###
     app.importTopo()
-
     app.mainloop()

examples/mobility.py

@@ -19,14 +19,13 @@ to-do:
 - think about clearing last hop - why doesn't that work?
 """
 
+from random import randint
 
 from mininet.net import Mininet
 from mininet.node import OVSSwitch
 from mininet.topo import LinearTopo
 from mininet.log import info, output, warn, setLogLevel
 
-from random import randint
-
 
 class MobilitySwitch( OVSSwitch ):
     "Switch that can reattach and rename interfaces"
@@ -38,6 +37,7 @@ class MobilitySwitch( OVSSwitch ):
         del self.intfs[ port ]
         del self.nameToIntf[ intf.name ]
 
+    # pylint: disable=arguments-differ
     def addIntf( self, intf, rename=False, **kwargs ):
         "Add (and reparent) an interface"
         OVSSwitch.addIntf( self, intf, **kwargs )
@@ -132,6 +132,7 @@ def mobilityTest():
         old = new
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     mobilityTest()

examples/multilink.py

@@ -21,6 +21,7 @@ def runMultiLink():
 class simpleMultiLinkTopo( Topo ):
     "Simple topology with multiple links"
 
+    # pylint: disable=arguments-differ
     def build( self, n, **_kwargs ):
         h1, h2 = self.addHost( 'h1' ), self.addHost( 'h2' )
         s1 = self.addSwitch( 's1' )
@@ -29,6 +30,7 @@ class simpleMultiLinkTopo( Topo ):
             self.addLink( s1, h1 )
             self.addLink( s1, h2 )
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     runMultiLink()

examples/multiping.py

@@ -8,14 +8,14 @@ multiple hosts and monitor their output interactively for a period=
 of time.
 """
 
+from select import poll, POLLIN
+from time import time
 
 from mininet.net import Mininet
 from mininet.node import Node
 from mininet.topo import SingleSwitchTopo
 from mininet.log import info, setLogLevel
 
-from select import poll, POLLIN
-from time import time
 
 def chunks( l, n ):
     "Divide list l into chunks of size n - thanks Stackoverflow"
@@ -59,7 +59,7 @@ def multiping( netsize, chunksize, seconds):
     # Start pings
     for subnet in subnets:
         ips = [ host.IP() for host in subnet ]
-        #adding bogus to generate packet loss
+        # adding bogus to generate packet loss
         ips.append( '10.0.0.200' )
         for host in subnet:
             startpings( host, ips )

examples/multipoll.py

@@ -6,15 +6,15 @@ monitoring them
 """
 
 
+from time import time
+from select import poll, POLLIN
+from subprocess import Popen, PIPE
+
 from mininet.topo import SingleSwitchTopo
 from mininet.net import Mininet
 from mininet.log import info, setLogLevel
 from mininet.util import decode
 
-from time import time
-from select import poll, POLLIN
-from subprocess import Popen, PIPE
-
 
 def monitorFiles( outfiles, seconds, timeoutms ):
     "Monitor set of files and return [(host, line)...]"

examples/multitest.py

@@ -17,6 +17,7 @@ def ifconfigTest( net ):
     for host in hosts:
         info( host.cmd( 'ifconfig' ) )
 
+
 if __name__ == '__main__':
     lg.setLogLevel( 'info' )
     info( "*** Initializing Mininet and kernel modules\n" )

examples/natnet.py

@@ -27,6 +27,7 @@ from mininet.util import irange
 
 class InternetTopo(Topo):
     "Single switch connected to n hosts."
+    # pylint: disable=arguments-differ
     def build(self, n=2, **_kwargs ):
         # set up inet switch
         inetSwitch = self.addSwitch('s0')
@@ -62,6 +63,7 @@ def run():
     CLI(net)
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel('info')
     run()

examples/numberedports.py

@@ -75,6 +75,7 @@ def testPortNumbering():
     info( '*** Stopping network\n' )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     testPortNumbering()

examples/popen.py

@@ -28,6 +28,7 @@ def monitorhosts( hosts=5 ):
     # Done
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     monitorhosts( hosts=5 )

examples/popenpoll.py

@@ -2,13 +2,14 @@
 
 "Monitor multiple hosts using popen()/pmonitor()"
 
+from time import time
+from signal import SIGINT
+
 from mininet.net import Mininet
 from mininet.topo import SingleSwitchTopo
 from mininet.util import pmonitor
 from mininet.log import setLogLevel, info
 
-from time import time
-from signal import SIGINT
 
 def pmonitorTest( N=3, seconds=10 ):
     "Run pings and monitor multiple hosts using pmonitor"
@@ -31,6 +32,7 @@ def pmonitorTest( N=3, seconds=10 ):
                 p.send_signal( SIGINT )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     pmonitorTest()

examples/scratchnet.py

@@ -8,6 +8,7 @@ but it exposes the configuration details and allows customization.
 For most tasks, the higher-level API will be preferable.
 """
 
+from time import sleep
 
 from mininet.net import Mininet
 from mininet.node import Node
@@ -15,7 +16,6 @@ from mininet.link import Link
 from mininet.log import setLogLevel, info
 from mininet.util import quietRun
 
-from time import sleep
 
 def scratchNet( cname='controller', cargs='-v ptcp:' ):
     "Create network from scratch using Open vSwitch."
@@ -62,6 +62,7 @@ def scratchNet( cname='controller', cargs='-v ptcp:' ):
     switch.deleteIntfs()
     info( '\n' )
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     info( '*** Scratch network demo (kernel datapath)\n' )

examples/scratchnetuser.py

@@ -66,6 +66,7 @@ def scratchNetUser( cname='controller', cargs='ptcp:' ):
     switch.deleteIntfs()
     info( '\n' )
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     info( '*** Scratch network demo (user datapath)\n' )

examples/simpleperf.py

@@ -9,6 +9,7 @@ iperf will hang indefinitely if the TCP handshake fails
 to complete.
 """
 
+from sys import argv
 
 from mininet.topo import Topo
 from mininet.net import Mininet
@@ -17,7 +18,6 @@ from mininet.link import TCLink
 from mininet.util import dumpNodeConnections
 from mininet.log import setLogLevel, info
 
-from sys import argv
 
 # It would be nice if we didn't have to do this:
 # pylint: disable=arguments-differ
@@ -54,6 +54,7 @@ def perfTest( lossy=True ):
     net.iperf( ( h1, h4 ), l4Type='UDP' )
     net.stop()
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     # Prevent test_simpleperf from failing due to packet loss

examples/sshd.py

@@ -47,6 +47,7 @@ def connectToRootNS( network, switch, ip, routes ):
     for route in routes:
         root.cmd( 'route add -net ' + route + ' dev ' + str( intf ) )
 
+# pylint: disable=too-many-arguments
 def sshd( network, cmd='/usr/sbin/sshd', opts='-D',
           ip='10.123.123.1/32', routes=None, switch=None ):
     """Start a network, connect it to root ns, and run sshd on all hosts.
@@ -73,6 +74,7 @@ def sshd( network, cmd='/usr/sbin/sshd', opts='-D',
         host.cmd( 'kill %' + cmd )
     network.stop()
 
+
 if __name__ == '__main__':
     lg.setLogLevel( 'info')
     net = TreeNet( depth=1, fanout=4 )

examples/treeping64.py

@@ -38,6 +38,7 @@ def treePing64():
         info( "%s: %d%% packet loss\n" % ( name, results[ name ] ) )
     info( '\n' )
 
+
 if __name__ == '__main__':
     setLogLevel( 'info' )
     treePing64()

examples/vlanhost.py

@@ -24,14 +24,18 @@ Usage (example uses VLAN ID=1000):
 
 """
 
+from sys import exit  # pylint: disable=redefined-builtin
+
 from mininet.node import Host
 from mininet.topo import Topo
 from mininet.util import quietRun
 from mininet.log import error
 
+
 class VLANHost( Host ):
     "Host connected to VLAN interface"
 
+    # pylint: disable=arguments-differ
     def config( self, vlan=100, **params ):
         """Configure VLANHost according to (optional) parameters:
            vlan: VLAN ID for default interface"""
@@ -54,6 +58,7 @@ class VLANHost( Host ):
 
         return r
 
+
 hosts = { 'vlan': VLANHost }
 
 
@@ -101,6 +106,7 @@ def exampleCustomTags():
     CLI( net )
     net.stop()
 
+
 if __name__ == '__main__':
     import sys
     from functools import partial

mininet/cli.py

@@ -47,7 +47,7 @@ class CLI( Cmd ):
     prompt = 'mininet> '
 
     def __init__( self, mininet, stdin=sys.stdin, script=None,
-                  *args, **kwargs ):
+                  **kwargs ):
         """Start and run interactive or batch mode CLI
            mininet: Mininet network object
            stdin: standard input for CLI
@@ -59,7 +59,7 @@ class CLI( Cmd ):
         self.inPoller = poll()
         self.inPoller.register( stdin )
         self.inputFile = script
-        Cmd.__init__( self, *args, stdin=stdin, **kwargs )
+        Cmd.__init__( self, stdin=stdin, **kwargs )
         info( '*** Starting CLI:\n' )
 
         if self.inputFile:
@@ -79,6 +79,7 @@ class CLI( Cmd ):
             return
         cls.readlineInited = True
         try:
+            # pylint: disable=import-outside-toplevel
             from readline import ( read_history_file, write_history_file,
                                    set_history_length )
         except ImportError:
@@ -141,7 +142,7 @@ class CLI( Cmd ):
         '  mininet> xterm h2\n\n'
     )
 
-    def do_help( self, line ):
+    def do_help( self, line ):  # pylint: disable=arguments-differ
         "Describe available CLI commands."
         Cmd.do_help( self, line )
         if line == '':
@@ -173,6 +174,7 @@ class CLI( Cmd ):
         """Evaluate a Python expression.
            Node names may be used, e.g.: py h1.cmd('ls')"""
         try:
+            # pylint: disable=eval-used
             result = eval( line, globals(), self.getLocals() )
             if not result:
                 return
@@ -467,10 +469,10 @@ class CLI( Cmd ):
                 node.sendInt()
             except select.error as e:
                 # pylint: disable=unpacking-non-sequence
+                # pylint: disable=unbalanced-tuple-unpacking
                 errno_, errmsg = e.args
-                # pylint: enable=unpacking-non-sequence
                 if errno_ != errno.EINTR:
-                    error( "select.error: %d, %s" % (errno_, errmsg) )
+                    error( "select.error: %s, %s" % (errno_, errmsg) )
                     node.sendInt()
 
     def precmd( self, line ):
@@ -488,3 +490,4 @@ def isReadable( poller ):
         mask = fdmask[ 1 ]
         if mask & POLLIN:
             return True
+        return False

mininet/link.py

@@ -24,9 +24,14 @@ TCIntf: interface with bandwidth limiting and delay via tc
 Link: basic link class for creating veth pairs
 """
 
+import re
+
 from mininet.log import info, error, debug
 from mininet.util import makeIntfPair
-import re
+
+# Make pylint happy:
+# pylint: disable=too-many-arguments
+
 
 class Intf( object ):
 
@@ -170,7 +175,7 @@ class Intf( object ):
         name, value = list( param.items() )[ 0 ]
         f = getattr( self, method, None )
         if not f or value is None:
-            return
+            return None
         if isinstance( value, list ):
             result = f( *value )
         elif isinstance( value, dict ):
@@ -311,6 +316,7 @@ class TCIntf( Intf ):
         debug(" *** executing command: %s\n" % c)
         return self.cmd( c )
 
+    # pylint: disable=arguments-differ
     def config( self, bw=None, delay=None, jitter=None, loss=None,
                 gro=False, txo=True, rxo=True,
                 speedup=0, use_hfsc=False, use_tbf=False,
@@ -351,7 +357,7 @@ class TCIntf( Intf ):
         # Question: what happens if we want to reset things?
         if ( bw is None and not delay and not loss
              and max_queue_size is None ):
-            return
+            return None
 
         # Clear existing configuration
         tcoutput = self.tc( '%s qdisc show dev %s' )
@@ -533,6 +539,10 @@ class OVSLink( Link ):
 
     def __init__( self, node1, node2, **kwargs ):
         "See Link.__init__() for options"
+        try:
+            OVSSwitch
+        except NameError:
+            # pylint: disable=import-outside-toplevel,cyclic-import
             from mininet.node import OVSSwitch
         self.isPatchLink = False
         if ( isinstance( node1, OVSSwitch ) and
@@ -541,6 +551,7 @@ class OVSLink( Link ):
             kwargs.update( cls1=OVSIntf, cls2=OVSIntf )
         Link.__init__( self, node1, node2, **kwargs )
 
+    # pylint: disable=arguments-differ, signature-differs
     def makeIntfPair( self, *args, **kwargs ):
         "Usually delegated to OVSSwitch"
         if self.isPatchLink:

mininet/log.py

@@ -20,7 +20,7 @@ LEVELS = { 'debug': logging.DEBUG,
 # change this to logging.INFO to get printouts when running unit tests
 LOGLEVELDEFAULT = OUTPUT
 
-#default: '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
+# default: '%(asctime)s - %(name)s - %(levelname)s - %(message)s'
 LOGMSGFORMAT = '%(message)s'
 
 
@@ -51,7 +51,7 @@ class StreamHandlerNoNewline( logging.StreamHandler ):
             self.flush()
         except ( KeyboardInterrupt, SystemExit ):
             raise
-        except:
+        except:  # noqa pylint: disable=bare-except
             self.handleError( record )
 
 
@@ -137,13 +137,14 @@ class MininetLogger( Logger, object ):
 
            logger.warning("Houston, we have a %s", "cli output", exc_info=1)
         """
-        if self.manager.disable >= OUTPUT:
+        if getattr( self.manager, 'disabled', 0 ) >= OUTPUT:
             return
         if self.isEnabledFor( OUTPUT ):
             self._log( OUTPUT, msg, args, kwargs )
 
     # pylint: enable=method-hidden
 
+
 lg = MininetLogger()
 
 # Make things a bit more convenient by adding aliases
@@ -168,6 +169,7 @@ def makeListCompatible( fn ):
     setattr( newfn, '__doc__', fn.__doc__ )
     return newfn
 
+
 _loggers = lg.info, lg.output, lg.warn, lg.error, lg.debug
 _loggers = tuple( makeListCompatible( logger )
                   for logger in _loggers )

mininet/moduledeps.py

@@ -1,8 +1,11 @@
 "Module dependency utility functions for Mininet."
 
+from os import environ
+from sys import exit  # pylint: disable=redefined-builtin
+
 from mininet.util import quietRun, BaseString
 from mininet.log import info, error, debug
-from os import environ
+
 
 def lsmod():
     "Return output of lsmod."
@@ -18,6 +21,7 @@ def modprobe( mod ):
        mod: module string"""
     return quietRun( [ 'modprobe', mod ] )
 
+
 OF_KMOD = 'ofdatapath'
 OVS_KMOD = 'openvswitch_mod'  # Renamed 'openvswitch' in OVS 1.7+/Linux 3.5+
 TUN = 'tun'

mininet/net.py

@@ -92,6 +92,7 @@ import select
 import signal
 import random
 
+from sys import exit  # pylint: disable=redefined-builtin
 from time import sleep
 from itertools import chain, groupby
 from math import ceil
@@ -113,6 +114,7 @@ VERSION = "2.3.0a1"
 class Mininet( object ):
     "Network emulation with hosts spawned in network namespaces."
 
+    # pylint: disable=too-many-arguments
     def __init__( self, topo=None, switch=OVSKernelSwitch, host=Host,
                   controller=DefaultController, link=Link, intf=Intf,
                   build=True, xterms=False, cleanup=False, ipBase='10.0.0.0/8',

mininet/node.py

@@ -57,7 +57,10 @@ import pty
 import re
 import signal
 import select
+from distutils.version import StrictVersion
+from re import findall
 from subprocess import Popen, PIPE
+from sys import exit  # pylint: disable=redefined-builtin
 from time import sleep
 
 from mininet.log import info, error, warn, debug
@@ -66,8 +69,10 @@ from mininet.util import ( quietRun, errRun, errFail, moveIntf, isShellBuiltin,
                            encode, getincrementaldecoder, Python3, which )
 from mininet.moduledeps import moduleDeps, pathCheck, TUN
 from mininet.link import Link, Intf, TCIntf, OVSIntf
-from re import findall
+
-from distutils.version import StrictVersion
+
+# pylint: disable=too-many-arguments
+
 
 class Node( object ):
     """A virtual network node is simply a shell in a network namespace.
@@ -94,9 +99,13 @@ class Node( object ):
         # Stash configuration parameters for future reference
         self.params = params
 
-        self.intfs = {}  # dict of port numbers to interfaces
+        # dict of port numbers to interfacse
-        self.ports = {}  # dict of interfaces to port numbers
+        self.intfs = {}
-                         # replace with Port objects, eventually ?
+
+        # dict of interfaces to port numbers
+        # todo: replace with Port objects, eventually ?
+        self.ports = {}
+
         self.nameToIntf = {}  # dict of interface names to Intfs
 
         # Make pylint happy
@@ -284,6 +293,7 @@ class Node( object ):
            returns: result of poll()"""
         if len( self.readbuf ) == 0:
             return self.pollOut.poll( timeoutms )
+        return None
 
     def sendCmd( self, *args, **kwargs ):
         """Send a command, followed by a command to echo a sentinel,
@@ -377,6 +387,7 @@ class Node( object ):
             return self.waitOutput( verbose )
         else:
             warn( '(%s exited - ignoring cmd%s)\n' % ( self, args ) )
+        return None
 
     def cmdPrint( self, *args):
         """Call cmd and printing its output
@@ -469,6 +480,7 @@ class Node( object ):
         else:
             warn( '*** defaultIntf: warning:', self.name,
                   'has no interfaces\n' )
+        return None
 
     def intf( self, intf=None ):
         """Return our interface object with given string name,
@@ -582,10 +594,10 @@ class Node( object ):
            value may also be list or dict"""
         name, value = list( param.items() )[ 0 ]
         if value is None:
-            return
+            return None
         f = getattr( self, method, None )
         if not f:
-            return
+            return None
         if isinstance( value, list ):
             result = f( *value )
         elif isinstance( value, dict ):
@@ -653,11 +665,12 @@ class Node( object ):
     @classmethod
     def checkSetup( cls ):
         "Make sure our class and superclasses are set up"
-        while cls and not getattr( cls, 'isSetup', True ):
+        clas = cls
-            cls.setup()
+        while clas and not getattr( clas, 'isSetup', True ):
-            cls.isSetup = True
+            clas.setup()
+            clas.isSetup = True
             # Make pylint happy
-            cls = getattr( type( cls ), '__base__', None )
+            clas = getattr( type( clas ), '__base__', None )
 
     @classmethod
     def setup( cls ):
@@ -838,6 +851,7 @@ class CPULimitedHost( Host ):
         errFail( 'cgclassify -g cpuset:/%s %s' % (
                  self.name, self.pid ) )
 
+    # pylint: disable=arguments-differ
     def config( self, cpu=-1, cores=None, **params ):
         """cpu: desired overall system CPU fraction
            cores: (real) core(s) this host can run on
@@ -930,6 +944,7 @@ class Switch( Node ):
         else:
             error( '*** Error: %s has execed and cannot accept commands' %
                    self.name )
+        return None
 
     def connected( self ):
         "Is the switch connected to a controller? (override this method)"
@@ -1115,6 +1130,7 @@ class OVSSwitch( Switch ):
         if self.batch:
             cmd = ' '.join( str( arg ).strip() for arg in args )
             self.commands.append( cmd )
+            return None
         else:
             return self.cmd( 'ovs-vsctl', *args, **kwargs )
 
@@ -1302,7 +1318,7 @@ class OVSBridge( OVSSwitch ):
         "Are we forwarding yet?"
         if self.stp:
             status = self.dpctl( 'show' )
-            return 'STP_FORWARD' in status and not 'STP_LEARN' in status
+            return 'STP_FORWARD' in status and 'STP_LEARN' not in status
         else:
             return True
 
@@ -1429,6 +1445,7 @@ class Controller( Node ):
                   ' 1>' + cout + ' 2>' + cout + ' &' )
         self.execed = False
 
+    # pylint: disable=arguments-differ,signature-differs
     def stop( self, *args, **kwargs ):
         "Stop controller."
         self.cmd( 'kill %' + self.command )
@@ -1479,7 +1496,7 @@ class NOX( Controller ):
             warn( 'warning: no NOX modules specified; '
                   'running packetdump only\n' )
             noxArgs = [ 'packetdump' ]
-        elif type( noxArgs ) not in ( list, tuple ):
+        elif not isinstance( noxArgs, ( list, tuple ) ):
             noxArgs = [ noxArgs ]
 
         if 'NOX_CORE_DIR' not in os.environ:
@@ -1505,7 +1522,7 @@ class Ryu( Controller ):
             warn( 'warning: no Ryu modules specified; '
                   'running simple_switch only\n' )
             ryuArgs = [ ryuCoreDir + 'simple_switch.py' ]
-        elif type( ryuArgs ) not in ( list, tuple ):
+        elif not isinstance( ryuArgs, ( list, tuple ) ):
             ryuArgs = [ ryuArgs ]
 
         Controller.__init__( self, name,
@@ -1532,6 +1549,7 @@ class RemoteController( Controller ):
         "Overridden to do nothing."
         return
 
+    # pylint: disable=arguments-differ
     def stop( self ):
         "Overridden to do nothing."
         return
@@ -1563,6 +1581,7 @@ class RemoteController( Controller ):
         else:
             return True
 
+
 DefaultControllers = ( Controller, OVSController )
 
 def findController( controllers=DefaultControllers ):
@@ -1570,6 +1589,7 @@ def findController( controllers=DefaultControllers ):
     for controller in controllers:
         if controller.isAvailable():
             return controller
+    return None
 
 def DefaultController( name, controllers=DefaultControllers, **kwargs ):
     "Find a controller that is available and instantiate it"

mininet/nodelib.py

@@ -102,6 +102,7 @@ class NAT( Node ):
             # hopefully this won't disconnect you
             self.cmd( 'service network-manager restart || netplan apply' )
 
+    # pylint: disable=arguments-differ
     def config( self, **params ):
         """Configure the NAT and iptables"""
 

mininet/term.py

@@ -50,7 +50,7 @@ def makeTerm( node, title='Node', term='xterm', display=None, cmd='bash'):
     }
     if term not in cmds:
         error( 'invalid terminal type: %s' % term )
-        return
+        return None
     display, tunnel = tunnelX11( node, display )
     if display is None:
         return []

mininet/test/runner.py

@@ -25,6 +25,7 @@ def runTests( testDir, verbosity=1 ):
                 .run( testSuite ).wasSuccessful() )
     sys.exit( 0 if success else 1 )
 
+
 if __name__ == '__main__':
     setLogLevel( 'warning' )
     # get the directory containing example tests

mininet/test/test_hifi.py

@@ -45,7 +45,7 @@ class testOptionsTopoCommon( object ):
     @staticmethod
     def tearDown():
         "Clean up if necessary"
-        if sys.exc_info != ( None, None, None ):
+        if sys.exc_info() != ( None, None, None ):
             cleanup()
 
     def runOptionsTopoTest( self, n, msg, hopts=None, lopts=None ):
@@ -95,7 +95,7 @@ class testOptionsTopoCommon( object ):
         CPU_FRACTION = 0.1
         CPU_TOLERANCE = 0.8  # CPU fraction below which test should fail
         hopts = { 'cpu': CPU_FRACTION }
-        #self.runOptionsTopoTest( N, hopts=hopts )
+        # self.runOptionsTopoTest( N, hopts=hopts )
 
         mn = Mininet( SingleSwitchOptionsTopo( n=N, hopts=hopts ),
                       host=CPULimitedHost, switch=self.switchClass,
@@ -118,7 +118,7 @@ class testOptionsTopoCommon( object ):
                 % ( CPU_FRACTION * 100, hostUsage, N, hoptsStr,
                     self.switchClass ) )
         for pct in results:
-            #divide cpu by 100 to convert from percentage to fraction
+            # divide cpu by 100 to convert from percentage to fraction
             self.assertWithinTolerance( pct/100, CPU_FRACTION,
                                         CPU_TOLERANCE, msg )
 
@@ -263,6 +263,7 @@ class testOptionsTopoUserspace( testOptionsTopoCommon, unittest.TestCase ):
     longMessage = True
     switchClass = UserSwitch
 
+
 if __name__ == '__main__':
     setLogLevel( 'warning' )
     unittest.main()

mininet/test/test_nets.py

@@ -26,7 +26,7 @@ class testSingleSwitchCommon( object ):
     @staticmethod
     def tearDown():
         "Clean up if necessary"
-        if sys.exc_info != ( None, None, None ):
+        if sys.exc_info() != ( None, None, None ):
             cleanup()
 
     def testMinimal( self ):

mininet/test/test_ptyleak.py

@@ -26,6 +26,7 @@ class TestPtyLeak( unittest.TestCase ):
             assert ( host.slave, host.master ) == oldptys
         net.stop()
 
+
 if __name__ == '__main__':
     unittest.main()
     cleanup()

mininet/test/test_switchdpidassignment.py

@@ -24,7 +24,7 @@ class TestSwitchDpidAssignmentOVS( unittest.TestCase ):
         "Clean up if necessary"
         # satisfy pylint
         assert self
-        if sys.exc_info != ( None, None, None ):
+        if sys.exc_info() != ( None, None, None ):
             cleanup()
 
     def testDefaultDpid( self ):
@@ -95,6 +95,7 @@ class testSwitchUserspace( TestSwitchDpidAssignmentOVS ):
     "Test dpid assignment of Userspace switch."
     switchClass = UserSwitch
 
+
 if __name__ == '__main__':
     setLogLevel( 'warning' )
     unittest.main()

mininet/test/test_util.py

@@ -35,5 +35,6 @@ class testQuietRun( unittest.TestCase ):
             output = quietRun(testQuietRun.getEchoCmd( n ) )
             self.assertEqual( n, len( output ) )
 
+
 if __name__ == "__main__":
     unittest.main()

mininet/test/test_walkthrough.py

@@ -6,14 +6,16 @@ Tests for the Mininet Walkthrough
 TODO: missing xterm test
 """
 
-import unittest
 import os
 import re
-from mininet.util import quietRun, pexpect
+import unittest
-from mininet.clean import cleanup
+
 from distutils.version import StrictVersion
 from sys import stdout
 
+from mininet.util import quietRun, pexpect
+from mininet.clean import cleanup
+
 
 def tsharkVersion():
     "Return tshark version"
@@ -74,7 +76,7 @@ class testWalkthrough( unittest.TestCase ):
         p.expect( self.prompt )
         # net command
         p.sendline( 'net' )
-        expected = [ x for x in nodes ]
+        expected = list( nodes )
         while len( expected ) > 0:
             index = p.expect( expected )
             node = p.match.group( 0 )
@@ -110,7 +112,7 @@ class testWalkthrough( unittest.TestCase ):
         ifcount = 0
         while True:
             index = p.expect( interfaces )
-            if index == 0 or index == 3:
+            if index in (0, 3):
                 ifcount += 1
             elif index == 1:
                 self.fail( 's1 interface displayed in "h1 ifconfig"' )
@@ -126,7 +128,7 @@ class testWalkthrough( unittest.TestCase ):
             index = p.expect( interfaces )
             if index == 0:
                 self.fail( 'h1 interface displayed in "s1 ifconfig"' )
-            elif index == 1 or index == 2 or index == 3:
+            elif index in (1, 2, 3):
                 ifcount += 1
             else:
                 break
@@ -309,7 +311,7 @@ class testWalkthrough( unittest.TestCase ):
         ifcount = 0
         while True:
             index = p.expect( interfaces )
-            if index == 1 or index == 3:
+            if index in (1, 3):
                 ifcount += 1
             elif index == 0:
                 self.fail( 'h1 interface displayed in "s1 ifconfig"' )

mininet/topo.py

@@ -13,6 +13,9 @@ setup for testing, and can even be emulated with the Mininet package.
 
 from mininet.util import irange, natural, naturalSeq
 
+# pylint: disable=too-many-arguments
+
+
 class MultiGraph( object ):
     "Utility class to track nodes and edges - replaces networkx.MultiGraph"
 

mininet/util.py

@@ -1,19 +1,23 @@
 "Utility functions for Mininet."
 
+import codecs
+import os
+import re
+import sys
 
-from mininet.log import output, info, error, warn, debug
+from fcntl import fcntl, F_GETFL, F_SETFL
-
+from functools import partial
-from time import sleep
+from os import O_NONBLOCK
 from resource import getrlimit, setrlimit, RLIMIT_NPROC, RLIMIT_NOFILE
 from select import poll, POLLIN, POLLHUP
 from subprocess import call, check_call, Popen, PIPE, STDOUT
-import re
+from sys import exit  # pylint: disable=redefined-builtin
-from fcntl import fcntl, F_GETFL, F_SETFL
+from time import sleep
-from os import O_NONBLOCK
+
-import os
+from mininet.log import output, info, error, warn, debug
-from functools import partial
+
-import sys
+# pylint: disable=too-many-arguments
-import codecs
+
 
 # Python 2/3 compatibility
 
@@ -454,6 +458,7 @@ def pmonitor(popens, timeoutms=500, readline=True,
         poller.register( fd, POLLIN )
         flags = fcntl( fd, F_GETFL )
         fcntl( fd, F_SETFL, flags | O_NONBLOCK )
+    # pylint: disable=too-many-nested-blocks
     while popens:
         fds = poller.poll( timeoutms )
         if fds:
@@ -665,7 +670,6 @@ def ensureRoot():
     if os.getuid() != 0:
         error( '*** Mininet must run as root.\n' )
         exit( 1 )
-    return
 
 def waitListening( client=None, server='127.0.0.1', port=80, timeout=None ):
     """Wait until server is listening on port.