diff --git a/examples/nat.py b/examples/nat.py
index 3c1f1cf..df11fc2 100755
--- a/examples/nat.py
+++ b/examples/nat.py
@@ -6,7 +6,6 @@ Example to create a Mininet topology and connect it to the internet via NAT
 
 from mininet.cli import CLI
 from mininet.log import lg
-from mininet.node import Node
 from mininet.topolib import TreeNet
 
 if __name__ == '__main__':
diff --git a/mininet/nodelib.py b/mininet/nodelib.py
index 682b608..b452a47 100644
--- a/mininet/nodelib.py
+++ b/mininet/nodelib.py
@@ -9,7 +9,6 @@ from mininet.log import info, warn
 from mininet.moduledeps import pathCheck
 from mininet.util import quietRun
 
-import re
 
 class LinuxBridge( Switch ):
     "Linux Bridge (with optional spanning tree)"
@@ -138,7 +137,8 @@ class NAT( Node ):
         self.cmd( 'iptables -D FORWARD',
                   '-o', self.localIntf, '-d', self.subnet,'-j ACCEPT' )
         self.cmd( 'iptables -t nat -D POSTROUTING',
-                  '-s', self.subnet, '\'!\'', '-d', self.subnet, '-j MASQUERADE' )
+                  '-s', self.subnet, '\'!\'', '-d', self.subnet,
+                  '-j MASQUERADE' )
         # Put the forwarding state back to what it was
         self.cmd( 'sysctl net.ipv4.ip_forward=%s' % self.forwardState )
         super( NAT, self ).terminate()
diff --git a/mininet/topolib.py b/mininet/topolib.py
index 8a2542d..9a05617 100644
--- a/mininet/topolib.py
+++ b/mininet/topolib.py
@@ -67,7 +67,8 @@ class TorusTopo( Topo ):
                 switch = switches[ i, j ] = self.addSwitch(
                     's' + loc, dpid='%x' % dpid )
                 for k in range( 0, n ):
-                    host = hosts[ i, j, k ] = self.addHost( genHostName( loc, k + 1 ) )
+                    host = hosts[ i, j, k ] = self.addHost(
+                        genHostName( loc, k + 1 ) )
                     self.addLink( host, switch )
         # Connect switches
         for i in range( 0, x ):