extracting image from the content in my db

[lip365]

Hello I'm trying to extract image from the content my user posts. (I know it sounds little bit odd)
I'm using wyswyg editor, django-ckeditor and when user posts text with images they are grouped as content. So to display the content(image and text), I do {{post.content}}. But I want to thumbnail an image in the front page, if there's an image in context. So I'm trying to extract image from the content in my db.
This is my try,

from goose import Goose

class Post(models.Model):
    content = RichTextUploadingField(config_name='default')
    @property

    def thumbnail(self, content):
        g = Goose()
        thumbnail = g.extract(raw_html=self.content).top_image.src
        return thumbnail

to display the image,
I did <img src = "{{post.thumbnail}}" />but nothing shows up. no error, no image.
Is it possible to do the following feature with python goose? am I doing it wrong?