python - Django field refering to another field -

i'm make django model conditions. i've thought these fields

class condition(models.model):     model_name = charfield(max_length=100)     field_name = charfield(max_length=100)     value = charfield(max_length=100) 

so can create condition specific field (field_name) in specific model (model_name) equal value. thought there might solution already? instead of using field_name thought if possible refer directly field either through contenttype or else?

i know high level , code not model asking. simple examples

django signals determine when change happened. https://docs.djangoproject.com/en/dev/topics/signals/

here signals.py file in app managing person objects when users change:

from django.db import models anotherapp.models import *  def user_post_delete(sender, instance, **kwargs):     try:         if instance.username:             person_item = person.objects.get(username = instance.username)             person_item.django_user = none             person_item.save()     except:         pass  def user_post_save(sender, instance, **kwargs):     try:         if instance.username:             p, created = person.objects.get_or_create(                 username=instance.username)             p.django_user = instance             p.save()     except:         pass  models.signals.post_delete.connect(user_post_delete, sender=user) models.signals.post_save.connect(user_post_save, sender=user) 

django contenttypes relate condition object in question. https://docs.djangoproject.com/en/dev/ref/contrib/contenttypes/

here model using contenttypes:

from django.contrib.contenttypes.models import contenttype class comment(models.model):     message = models.textfield()     #removed fields not relevent     content_type = models.foreignkey(contenttype)     object_id = models.positiveintegerfield()     content_object = generic.genericforeignkey('content_type', 'object_id')     date_added = models.datetimefield('date_added',auto_now_add=true, editable=false)     date_updated = models.datetimefield('date_updated',auto_now_add=true, auto_now=true, editable=false) 

then in views.py/signals.py use contenttype model(ticket model name, , t.id id of ticket object:

new_comment = comment(     message = "test message",     content_type = contenttype.objects.get(model='ticket'),     object_id = t.id, ) new_comment.save() 

you want expand have simple boolean if condition met, or bit more , use model store results , come "5