Cleanup Files On Model Delete in Django

Code examples adopted from this blog

Attached files are not automatically deleted if your model has FileField or ImageField.

Create a cleanup function

import os
from django.core.files.storage import default_storage
from django.db.models import FileField

def file_cleanup(sender, **kwargs):
"""
File cleanup callback used to emulate the old delete
behavior using signals. Initially django deleted linked
files when an object containing a File/ImageField was deleted.

Usage:
>>> from django.db.models.signals import post_delete
>>> post_delete.connect(file_cleanup, sender=MyModel, dispatch_uid="mymodel.file_cleanup")
"""
for fieldname in sender._meta.get_all_field_names():
    try:
        field = sender._meta.get_field(fieldname)
    except:
        field = None
        if field and isinstance(field, FileField):
            inst = kwargs['instance']
            f = getattr(inst, fieldname)
            m = inst.__class__._default_manager
            if hasattr(f, 'path') and os.path.exists(f.path)\
            and not m.filter(**{'%s__exact' % fieldname: getattr(inst, fieldname)})\
            .exclude(pk=inst._get_pk_val()):
            try:
                default_storage.delete(f.path)
            except:
                pass

Add post_delete signal to catch model deletion event in models.py

from django.db import models
from django.db.models.signals import post_delete
from .utils import file_cleanup

... models code goes here ...

post_delete.connect(file_cleanup, sender=Image, dispatch_uid="gallery.image.file_cleanup")