Manually associate an existing file to a model FileField

FileField_manual_initialisation.py

# 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

@andrestone that was works for me:

file_path = "..."  # it should be relative path to your settings.MEDIA_ROOT  
article.file = file_path  
article.save()```

@CarliJoy much more better! Thanks!

@ncopiy It may works if the file is already saved in the dir your model file field expect.
But if you want to deal with InMemoryFile or StringIO content, this snippets should handle the model file field base path you defined. It a little more complicated though, so it depends on your needs.