How to delete old image when update ImageField?

Use django-cleanup

pip install django-cleanup

settings.py

INSTALLED_APPS = (
    ...
    'django_cleanup.apps.CleanupConfig', # should be placed after your apps

)

Before updating the model instance, you can use the delete method of FileField object. For example, if the FileField or ImageField is named as photo and your model instance is profile, then the following will remove the file from disk

profile.photo.delete(False)

For more clarification, here is the django doc

https://docs.djangoproject.com/en/1.11/ref/models/fields/#django.db.models.fields.files.FieldFile.delete

Use this custom save method in your model:

def save(self, *args, **kwargs):
    try:
        this = MyModelName.objects.get(id=self.id)
        if this.MyImageFieldName != self.MyImageFieldName:
            this.MyImageFieldName.delete()
    except: pass
    super(MyModelName, self).save(*args, **kwargs)

It works for me on my site. This problem was bothering me as well and I didn't want to make a cleanup script instead over good bookkeeping in the first place. Let me know if there are any problems with it.

You'll have to delete the old image manually.

The absolute path to the image is stored in your_image_field.path. So you'd do something like:

os.remove(your_image_field.path)

But, as a convenience, you can use the associated FieldFile object, which gives easy access to the underlying file, as well as providing a few convenience methods. See http://docs.djangoproject.com/en/dev/ref/models/fields/#filefield-and-fieldfile