diff --git a/plugins/libvirt/munin-libvirtpy b/plugins/libvirt/munin-libvirtpy
index 1ad2f488..d88db49f 100755
--- a/plugins/libvirt/munin-libvirtpy
+++ b/plugins/libvirt/munin-libvirtpy
@@ -1,57 +1,75 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
-# Revision 1.0  2008/05/16 - Steven Wagner
-# First functional release. Works for me.
-#
-# Revision 0.5  2008/05/01  - Julien Rottenberg
-# initial display of variables from libvirt
+"""
+=encoding utf8
 
-#python-libvirt is required
+=head1 NAME
+
+munin-libvirtpy - KVM Domain CPU Utilization
+
+
+=head1 CONFIGURATION
+
+Parsed environment variables:
+python-libvirt is required
+
+=head1 LICENSE
+
+GPLv3
+
+SPDX-License-Identifier: GPL-3.0-only
+
+
+=head1 AUTHORS
+
+Julien Rottenberg
+
+Steven Wagner
+
+
+=head1 MAGIC MARKERS
+
+ #%# capabilities=autoconf
+ #%# family=contrib
+
+=cut
+"""
 
 import libvirt
 import sys
 
 conn = libvirt.openReadOnly("qemu:///system")
-if conn == None:
-    print 'Failed to open connection to the hypervisor'
+if conn is None:
+    print('Failed to open connection to the hypervisor')
     sys.exit(1)
 
 try:
     (model, memory, cpus, mhz, nodes, socket, cores, threads) = conn.getInfo()
-except:
-    print 'getInfo failed'
+except BaseException as error:
+    print('getInfo failed: {}'.format(error), file=sys.stderr)
     sys.exit(1)
 
-#print
-#print "KVM running on %d %s %d mhz CPUs w/ %d MB RAM." % (cpus, model, mhz, memory)
-#print
-
 ids = conn.listDomainsID()
-if ids == None or len(ids) == 0:
-    print 'No running domains found.'
+if ids is None or len(ids) == 0:
+    print('No running domains found.', file=sys.stderr)
     sys.exit(1)
 
-
 if len(sys.argv) == 2:
     if sys.argv[1] == "config":
-        print "graph_title KVM Domain CPU Utilization"
-        print "graph_vlabel CPU use in seconds"
-        print "graph_args --base 1000"
-        print "graph_category virtualization"
+        print("graph_title KVM Domain CPU Utilization")
+        print("graph_vlabel CPU use in seconds")
+        print("graph_args --base 1000")
+        print("graph_category virtualization")
 
         for id in ids:
             dom = conn.lookupByID(id)
             nodeName = dom.name()
-            print "%s.type COUNTER" %(nodeName)
-            print "%s.label %s" %(nodeName, nodeName)
+            print("%s.type COUNTER" % (nodeName))
+            print("%s.label %s" % (nodeName, nodeName))
         sys.exit(0)
 
 for id in ids:
     dom = conn.lookupByID(id)
     state, maxMem, memory, numVirtCpu, cpuTime = dom.info()
     nodeName = dom.name()
-#    uuid = dom.UUID()
-#    ostype = dom.OSType()
-#    print """Domain: %s, %s state (%s), %d CPUs, %d seconds, %d milliseconds, mem/max (%d/%d) """ \
-#          % (nodeName, ostype, state, numVirtCpu, cpuTime/float(1000000000), cpuTime/float(1000000), memory, maxMem )
-    print "%s.value %d" % (nodeName, cpuTime/float(1000000))
+    print("%s.value %d" % (nodeName, cpuTime/float(1000000)))