Where should django manager code live?
I prefer to keep my models in models.py and managers in managers.py (forms in forms.py) all within the same app.  For more generic managers, I prefer to keep them in core.managers if they can be re-used for other apps.  In some of our larger apps with models/modelname.py that will contains a manager and the model code which doesn't seem bad.
This is a pretty simple django patterns question. My manager code usually lives in models.py, but what happens when models.py is really huge? Is there any other alternative pattern to letting your manager code live in models.py for maintainability and to avoid circular imports?
A question may be asked as to why models.py is so huge, but let's just assume it's size and breadth of utility is justified.