Uploading bulk data to data store

The documentation on how to upload bulk data to Google App Engine's data store: http://code.google.com/intl/es/appengine/docs/python/tools/uploadingdata.html

How to express relationships between models? How to support utf-8 in the bulk load?
Here is my loader.py

 
from appengine_django import InstallAppengineHelperForDjango
InstallAppengineHelperForDjango()
 
import datetime
from google.appengine.ext import db
from google.appengine.tools import bulkloader
 
from myapp.models import *
 
class MyLoader(bulkloader.Loader):
  def __init__(self):
    bulkloader.Loader.__init__(self, 'MyModel',
                               [('country',
                                  lambda x: Country.get_by_key_name(x)),
                                ('code',
                                  lambda x: unicode(x, 'utf-8')),
                                ('name',
                                  lambda x: unicode(x, 'utf-8'))
                               ])
 
loaders = [MyLoader]
 

The cvs:
ES, someCode, someName

The command line to upload the data:
.google_appengine/appcfg.py upload_data --config_file=loaders.py --filename=bulkdata.csv --kind=MyModel .

Problems I had: http://groups.google.com/group/google-appengine-python/browse_thread/thread/b524b5ad2cbecb30