Using crontab with django

I need to create a function for sending newsletters everyday from crontab. I've found two ways of doing this on the internet :

First - file placed in the django project folder:

#! /usr/bin/env python
import sys
import os

from django.core.management import setup_environ
import settings
setup_environ(settings)

from django.core.mail import send_mail
from project.newsletter.models import Newsletter, Address

def main(argv=None):
    if argv is None:
        argv = sys.argv

    newsletters = Newsletter.objects.filter(sent=False)
    message = 'Your newsletter.'

    adr = Address.objects.all()
    for a in adr:
        for n in newsletters:
            send_mail('System report',message, a ,['user@example.com'])

if __name__ == '__main__':
    main()

I'm not sure if it will work and I'm not sure how to run it. Let's say it's called run.py, so should I call it in cron with 0 0 * * * python /path/to/project/run.py ?

Second solution - create my send function anywhere (just like a normal django function), and then create a run.py script :

import sys
import os

os.environ['DJANGO_SETTINGS_MODULE'] = 'settings'

module_name = sys.argv[1]
function_name = ' '.join(sys.argv[2:])

exec('import %s' % module_name)
exec('%s.%s' % (module_name, function_name))

And then in cron call : 0 0 * * * python /path/to/project/run.py newsletter.views daily_job()

Which method will work, or which is better ?