gistfile1.py

class Parent(object):
  def log_message(self, string):
    self.c_instance.log_message(string) # Calling a C bridge
    
  def create_children(self):
    self.child1 = Child(self)
    self.child2 = Child2(self)
  
class Child(object):
  def __init__(self, parent):
    self.parent = parent
    self.grandchild1 = Grandchild(parent)
    self.parent.log_message("some message")
    
class Child2(object):
  def __init__(self, parent):
    self.parent = parent
    self.grandchild2 = Grandchild2(parent)
    self.parent.log_message("another message")
    
class Grandchild(object):
  def __init__(self):
    self.parent = parent
    self.parent.log_message("grandchild loaded")
    
class Grandchild2(object):
  def __init__(self, parent):
    self.parent = parent
    self.parent.log_message("grandchild loaded")