naming and binding (subtle Python 3 change)

[Alan G Isaac]

The example give at
http://docs.python.org/reference/executionmodel.html#naming-and-binding
remains unchanged at
http://docs.python.org/3.0/reference/executionmodel.html#naming-and-binding
but the change to Python 3 list comprehensions now means the example
will fail even with list comprehension syntax.  Should the example be
changed to make that clear?

Alan Isaac