@@ -, +, @@ 
---
 src/visualizer/model/visual-simulator-impl.cc | 14 ++++++++++----
 src/visualizer/visualizer/__init__.py         |  2 +-
 src/visualizer/visualizer/base.py             |  9 ++++-----
 src/visualizer/visualizer/core.py             |  8 ++++----
 src/visualizer/visualizer/hud.py              |  2 +-
 src/visualizer/visualizer/ipython_view.py     |  4 ++--
 src/visualizer/visualizer/plugins/olsr.py     |  2 +-
 src/visualizer/visualizer/svgitem.py          |  4 ++--
 8 files changed, 25 insertions(+), 20 deletions(-)
--- a/src/visualizer/model/visual-simulator-impl.cc	
+++ a/src/visualizer/model/visual-simulator-impl.cc	
@@ -112,11 +112,17 @@ VisualSimulatorImpl::IsFinished (void) const
 void
 VisualSimulatorImpl::Run (void)
 {
-  if (!Py_IsInitialized ()) 
+  if (!Py_IsInitialized ())
     {
-      const char *argv[] = { "python", NULL};
-      Py_Initialize ();
-      PySys_SetArgv (1, (char**) argv);
+      #if PY_MAJOR_VERSION >= 3
+        const wchar_t *argv[] = { L"python", NULL};
+        Py_Initialize ();
+        PySys_SetArgv (1, (wchar_t**) argv);
+      #else
+        const char *argv[] = { "python", NULL};
+        Py_Initialize ();
+        PySys_SetArgv (1, (char**) argv);
+      #endif
       PyRun_SimpleString (
                           "import visualizer\n"
                           "visualizer.start();\n"
--- a/src/visualizer/visualizer/__init__.py	
+++ a/src/visualizer/visualizer/__init__.py	
@@ -1,3 +1,3 @@ 
 
-from core import start, register_plugin, set_bounds, add_initialization_hook
+from .core import start, register_plugin, set_bounds, add_initialization_hook
 
--- a/src/visualizer/visualizer/base.py	
+++ a/src/visualizer/visualizer/base.py	
@@ -5,7 +5,6 @@ import ns.bridge
 import ns.internet
 import ns.mesh
 import ns.wimax
-import ns.wimax
 import ns.lte
 
 from gi.repository import GObject
@@ -126,15 +125,15 @@ def load_plugins():
             continue
         try:
             plugin_module = __import__(name)
-        except ImportError, ex:
-            print >> sys.stderr, "Could not load plugin %r: %s" % (filename, str(ex))
+        except ImportError as ex:
+            print("Could not load plugin %r: %s" % (filename, str(ex)), file=sys.stderr)
             continue
         try:
             plugin_func = plugin_module.register
         except AttributeError:
-            print >> sys.stderr, "Plugin %r has no 'register' function" % name
+            print("Plugin %r has no 'register' function" % name, file=sys.stderr)
         else:
-            #print >> sys.stderr, "Plugin %r registered" % name
+            #print("Plugin %r registered" % name, file=sys.stderr)
             register_plugin(plugin_func, name, plugin_module)
     sys.path = old_path
 
--- a/src/visualizer/visualizer/core.py	
+++ a/src/visualizer/visualizer/core.py	
@@ -61,10 +61,10 @@ try:
 except ImportError:
     ipython_view = None
 
-from base import InformationWindow, PyVizObject, Link, lookup_netdevice_traits, PIXELS_PER_METER
-from base import transform_distance_simulation_to_canvas, transform_point_simulation_to_canvas
-from base import transform_distance_canvas_to_simulation, transform_point_canvas_to_simulation
-from base import load_plugins, register_plugin, plugins
+from .base import InformationWindow, PyVizObject, Link, lookup_netdevice_traits, PIXELS_PER_METER
+from .base import transform_distance_simulation_to_canvas, transform_point_simulation_to_canvas
+from .base import transform_distance_canvas_to_simulation, transform_point_canvas_to_simulation
+from .base import load_plugins, register_plugin, plugins
 
 PI_OVER_2 = math.pi/2
 PI_TIMES_2 = math.pi*2
--- a/src/visualizer/visualizer/hud.py	
+++ a/src/visualizer/visualizer/hud.py	
@@ -1,5 +1,5 @@ 
-import core
 import math
+from . import core
 from gi.repository import Pango
 from gi.repository import Gtk
 from gi.repository import GooCanvas
--- a/src/visualizer/visualizer/ipython_view.py	
+++ a/src/visualizer/visualizer/ipython_view.py	
@@ -319,11 +319,11 @@ class IterableIPShell:
     @return none
     """
     stat = 0
-    if verbose or debug: print header+cmd
+    if verbose or debug: print(header+cmd)
     # flush stdout so we don't mangle python's buffering
     if not debug:
       input, output = os.popen4(cmd)
-      print output.read()
+      print(output.read())
       output.close()
       input.close()
 
--- a/src/visualizer/visualizer/plugins/olsr.py	
+++ a/src/visualizer/visualizer/plugins/olsr.py	
@@ -120,7 +120,7 @@ def populate_node_menu(viz, node, menu):
     ns3_node = ns.network.NodeList.GetNode(node.node_index)
     olsr = ns3_node.GetObject(ns.olsr.olsr.RoutingProtocol.GetTypeId())
     if olsr is None:
-        print "No OLSR"
+        print("No OLSR")
         return
 
     menu_item = Gtk.MenuItem("Show OLSR Routing Table")
--- a/src/visualizer/visualizer/svgitem.py	
+++ a/src/visualizer/visualizer/svgitem.py	
@@ -120,7 +120,7 @@ class SvgItem(GooCanvas.ItemSimple):
             self.changed(True)
 
         else:
-            raise AttributeError, 'unknown property %s' % pspec.name
+            raise AttributeError('unknown property %s' % pspec.name)
 
     def _size_changed(self):
         """!
@@ -172,7 +172,7 @@ class SvgItem(GooCanvas.ItemSimple):
             return self.height
 
         else:
-            raise AttributeError, 'unknown property %s' % pspec.name
+            raise AttributeError('unknown property %s' % pspec.name)
 
     def do_simple_paint(self, cr, bounds):
         """!
--