PyGraphViz

Planet-Lab nodes use Fedora 8 of Fedora 12.

So we cannot use

we use

```gv```

example:

Instead of:

```import pygraphviz```

we use:

```import gv```

We need to specify also the directory where is the library of graphviz by editing the PYTHONPATH

[uniroma2_fairvpn@planet-lab-node1]$ PYTHONPATH="/usr/lib/graphviz/python/" python ```