Django, download and store image in ImageField

gistfile1.py

image_url = og.get('image')
if image_url:
    import urllib2
    from django.core.files import File
    from django.core.files.temp import NamedTemporaryFile
    img_temp = NamedTemporaryFile(delete=False)
    img_temp.write(urllib2.urlopen(image_url).read())
    img_temp.flush()

    import os
    import urlparse
    img_filename = os.path.basename(urlparse.urlsplit(image_url).path)

    self.image.save(img_filename, File(img_temp), False)