Can I pass a python function as a function pointer to a function bound through Boost.Python?

Question

So if I have a function:

void foo(void(*fn)()) {
  fn();
}

Which I've added to my Boost.Python module:

boost::python::def(&foo);

Is there any way I can make something like this work in my python script:

def my_fn():
  print 'hello'

foo(my_fn)