Complete comments for expirelinks.py

 - fairly straightforward django-admin command

go/go/management/commands/expirelinks.py

+# Django Imports
 from django.core.management.base import BaseCommand
 from django.utils import timezone
-from go.models import URL
 
+# App Imports
+from go.models import URL
 
+# Define a new custom django-admin command
 class Command(BaseCommand):
+    # Define help text for this command
     help = 'Removes expired links from the database'
 
+    # The handle function handles the main component of the django-admin command
     def handle(self, *args, **options):
+        # Loop through a list of all URL objects that have expired
+        # (expires field is less than or equal to today's date)
         for toexpire in URL.objects.filter(expires__lte=timezone.now()):
+            # Delete the current URL
             toexpire.delete()