Django-taggit : How to delete unused tags ?

[Christine Bale]

Hey I have a problem with django-taggit, I want to know how can I delete unused tags In django ? (python 2.7.9 and Django 1.7.4)

heres is my code: models.py

from django.db import models
from updown.fields import RatingField
from taggit.managers import TaggableManager
from taggit.models import *
from django.db.models.signals import pre_delete

class Article(models.Model):
    titre = models.CharField(max_length=100)
    auteur = models.CharField(max_length=42)
    contenu = models.TextField(null=True)
    date = models.DateTimeField(auto_now_add=True, auto_now=False, verbose_name="Date de parution")
    image = models.ImageField(upload_to='article', default='article/amazarashi.jpeg')
    rating = RatingField(can_change_vote=True)
    tags = TaggableManager(blank=True)

    def __str__(self):
        return self.titre

def before_deleting(sender, instance, **kwargs):
    if not TaggedItem.objects.filter(tags=instance.tags):
        print "Deleting tag", instance
        instance.tags.delete()

pre_delete.connect(before_deleting, sender=TaggedItem)

here is my: views.py (I obviously imported my models.py to my views)

def innertag(request, id):
    tag = Tag.objects.get(id = id)
    articles = Article.objects.filter(tags=tag)
    context = {'tag': tag, 'articles': articles}
    populateContext(request, context)
    return render(request, 'innerajouter.html', context)

How can I reslove this problem I need to delete, the unused url of the tag and the tag itself. Any suggestion would be really helpful,