url2filefield.py

# https://gist.github.com/bryanchow/b25aeed8db9e82a68c920e66fd192536

try:
    from io import BytesIO
except ImportError:
    from cStringIO import cStringIO as BytesIO

import requests
from mimetypes import guess_extension
from django.core import files


def save_url_to_filefield(instance, fieldname, url, ensure_extension=True):
    """
    Fetch the passed-in URL and save it to a Django FileField/ImageField.

    Usage:
        instance = MyModel()
        save_url_to_filefield(instance, 'field', "https://some-url/")
    """
    response = requests.get(url)
    if response.status_code == requests.codes.ok:
        fp = BytesIO()
        fp.write(response.content)
        filename = url.split("/")[-1]
        if ensure_extension:
            extension = guess_extension(
                response.headers['content-type'].partition(';')[0].strip()
            )
            if not filename.endswith(extension):
                filename = "{}{}".format(filename, extension)
        field = getattr(instance, fieldname)
        field.save(filename, files.File(fp))
        return True
    return False