re-adding a Network to Nengo wipes out that variable in Python

[tcstewar]

The following script fails when run twice in Nengo:

Blah=1

import nef
net=nef.Network('Blah')
net.add_to_nengo()

print Blah

I believe what is happening is that when Nengo wipes out the old 'Blah' network when the script is run the second time, it also wipes out the variable Blah from the PythonInterpreter