Django Delete File when remove an Object & Delete Old File when updating an Object

models.py

'''
@jimmyromanticde
Note:
python 2.x Only
Django >= 1.4

Problem:
1. django cannot remove files when deleting an objects in models/database
2. django cannot update/replace/delete files when updating an objects in models/database

more about this solution https://docs.djangoproject.com/es/1.9/ref/signals/

'''

#put in your models header/top
from django.db.models.signals import pre_delete, pre_save
from django.dispatch.dispatcher import receiver
from django.core.files.storage import default_storage

#sample models. so it will be clear for you to understand
#i just put some field that what i think important for this problem

class Resume(models.Model):
    thumbs = models.ImageField(
        upload_to='uploads/thumbnails/', blank=True, null=True)
    ........


class ResumeImage(models.Model):
    resume = models.ForeignKey(Resume, related_name='resume_image')
    photo = models.ImageField(
        upload_to='uploads/resume/', blank=True, null=True)
    .......



class ResumeFile(models.Model):
    resume = models.ForeignKey(Resume, related_name='resume_file')
    files = models.FileField(
        upload_to='uploads/resumefile/', blank=True, null=True)
    .......



#you can put this anything you want as long as the models objects has been define.

#answer of case/problem 1. django cannot remove files when deleting an objects in models/database
@receiver(pre_delete, sender=Resume)
def ResumeMainDel(sender, instance, **kwargs):
    try:
        default_storage.delete(instance.thumbs.path)
        #when this resume are deleted. we need to remove all related files with this main Resume models
        instance.resume_file.all().delete()
        instance.resume_image.all().delete()
        instance.clean()
    except Exception,e:
        #keep track the error if there is something wrong with the code.
        #u can remove it later after the code has been clean/running well
        print e
        return False
    return True

#before remove a resumefile object. remove the file first.
@receiver(pre_delete, sender=ResumeFile)
def ResumeFileDel(sender, instance, **kwargs):
    try:
        default_storage.delete(instance.files.path)
        instance.clean()
    except Exception,er:
        #keep track the error if there is something wrong with the code.
        #u can remove it later after the code has been clean/running well
        print er
        return False
    return True

#before remove a resumeimage object. remove the file first.
@receiver(pre_delete, sender=ResumeImage)
def ResumeImageDel(sender, instance, **kwargs):
    try:
        default_storage.delete(instance.photo.path)
        instance.clean()
    except Exception,er:
        #keep track the error if there is something wrong with the code.
        #u can remove it later after the code has been clean/running well
        print er
        return False
    return True

#answer of case/problem 2. django cannot update/replace/delete files when updating an objects in models/database
@receiver(pre_save, sender=Resume)
def ResumeTumbsChange(sender, instance, *args, **kwargs):
    if not instance.pk:
        return
      
    try:
        obj = Resume.objects.get(id=instance.id)
    except Resume.DoesNotExist:
        # object is not in db, nothing to worry about
        return
        # is the save due to an update of the actual image file?
    if obj.thumbs and instance.thumbs and obj.thumbs != instance.thumbs:
        # delete the old image file from the storage in favor of the new file
         default_storage.delete(obj.thumbs.path)

#I hope it will be useful for you. comment me if im wrong