# Assuming you have a Article Model like this
# class Article(models.Model):
#   ... Some field
# 	media = models.FileField(upload_to="path_to_inner_media_folder", blank=True)

from django.core.files.base import ContentFile
import os

# Create an article with the associated model
new_article = Article()

original_file_path = 'path'
new_file_path = 'new_path'

fh = open(original_file_path, "r")
if fh:
	# Get the content of the file
	file_content = ContentFile(fh.read())
	# Set the media attribute of the article, but under an other path/filename
	new_article.media.save(new_file_path, file_content)
	# Save the article
	new_article.save()
# Close the file and delete it
fh.close()
if fh.closed:
	os.remove(unicode(fh.name))
	del fh