Pass code check with pylint=2.4.4 (#1012)

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()