from datetime import datetime
from django.contrib.sessions.models import Session
def delete_old_sessions():
    Session.objects.filter(expire_date__lt=datetime.now()).delete()
def run():
    delete_old_sessions()

#!/usr/bin/env python
"""
Project-wide Cron Job... A Command-line Django Script.

This script gets scheduled and run by cron (or whatever).
It then calls the `run` method of each app's cron module, 
if it exists (should be `appname/cron.py`)

This script should be invoked after setting the 
DJANGO_SETTINGS_MODULE environment variable.

You chould do this in a BASH script as follows:
    export DJANGO_SETTINGS_MODULE=mysite.settings
    python /path/to/mysite/cron.py
"""
from django.conf import settings
def my_import(name):
    '''
    __import__ helper function to import modules inside packages
    e.g.:  where name is something like 'package.module.mod_i_want',
           would return mod_i_want

    See: http://www.python.org/doc/2.5.2/lib/built-in-funcs.html
    '''
    mod = __import__(name)
    components = name.split('.')
    for comp in components[1:]:
        mod = getattr(mod, comp)
    return mod
def run():
    for app in settings.INSTALLED_APPS:
        if not app.startswith('django'):
            output_info = '%s.cron'%app
            ## Dynamically import a module called 'cron'
            ## from each INSTALLED_APP (if it exists)
            try:
                cron_mod = my_import(app+'.cron')
                output_info += '... FOUND'
                print output_info
                ## 3. Execute the cron's run method (if it exists)
                if hasattr(cron_mod, 'run'):
                    #print '---> calling run()'
                    cron_mod.run()
            except ImportError:
                # ignore packages that don't have a cron module
                output_info += '... SKIPPED'
                print output_info
if __name__ == "__main__":
    run()

#!/bin/bash
# This is a Django, Project-specific Cron script.
# Separate Projects would need a copy of this script 
# with appropriate Settings export statments.

PYTHONPATH="${PYTHONPATH}:/path/to/django/project/directory"
export PYTHONPATH
export DJANGO_SETTINGS_MODULE=mysite.settings
python/path/to/django/project/directory/mysite/cron.py

#m h  dom mon dow   command
  0   6    *        *      *     /path/to/django/project/directory/cron.sh