old_contents: # this is a namespace package
  try:
      import pkg_resources
      pkg_resources.declare_namespace(__name__)
  except ImportError:
      import pkgutil
      __path__ = pkgutil.extend_path(__path__, __name__)
  
new_contents: # this is a namespace package
  try:
      declare_namespace(__name__)
  except NameError:
      print "Failed to declare_namespace()"
  
subject: Update __init__.py