A bundle of questions from a Python newbie

[Paul Rubin]

Duncan Booth <duncan at NOSPAMrcp.co.uk> writes:
> The main differences between a coroutine and a generator are:
> 
> 1) Coroutines maintain their own stack. This allows a coroutine to yield 
> not just from the function you originally called, but also from any nested 
> function no matter how deep.
> Python's generators can only yield directly from the generator as they do 
> not attempt to maintain any kind of stack.

Is that right?  I thought the classic coroutine example is supposed to
also work with generators:

  def traverse(tree):
     if tree.left: traverse(tree.left)
     yield tree.value
     if tree(right) traverse(tree.right)

Am I missing something?