Django save image from url and connect with ImageField

from django.core.files import File
import os

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

...

def get_remote_image(self):
    if self.image_url and not self.image_file:
        result = urllib.urlretrieve(self.image_url)
        self.image_file.save(
                os.path.basename(self.image_url),
                File(open(result[0]))
                )
        self.save()

You can override the default save() method to automatically invoke get_remote_image().

See: https://docs.djangoproject.com/en/dev/topics/db/models/#overriding-model-methods