Embedded Document

==model.py==
class ContentRating(EmbeddedDocument):
    content = ReferenceField(Content)
    rating = FloatField(default=5000)



class Target(Document):
    age = IntField(min_value=20,max_value=60)
    gender = StringField(max_length=1,choices=['M','F'])
    location = GeoPointField()
    videos = ListField(EmbeddedDocumentField(ContentRating))

==django shell==
>>>cr1=ContentRating()
>>>cr1.content=Content.objects(title="Video3")
>>>
>>>for x in range(20,30):
...    t=Target()
...    t.age=x
...    t.gender='M'
...    t.location=[10,20]
...    t.videos.append(cr1)
...    t.save()

Traceback (most recent call last):
  File "<console>", line 7, in <module>
  File "/usr/local/lib/python2.6/dist-packages/mongoengine-0.4-py2.6.egg/mongoengine/document.py", line 73, in save
    self.validate()
  File "/usr/local/lib/python2.6/dist-packages/mongoengine-0.4-py2.6.egg/mongoengine/base.py", line 357, in validate
    field._validate(value)
  File "/usr/local/lib/python2.6/dist-packages/mongoengine-0.4-py2.6.egg/mongoengine/base.py", line 103, in _validate
    self.validate(value)
  File "/usr/local/lib/python2.6/dist-packages/mongoengine-0.4-py2.6.egg/mongoengine/fields.py", line 346, in validate
    raise ValidationError('Invalid ListField item (%s)' % str(item))
ValidationError: Invalid ListField item (ContentRating object)