brechin / django-computed-property

Computed Property Fields for Django

django-computed-property

Computed Property Fields for Django

Inspired by Google Cloud Datastore NDB Computed Properties.

Automatically store a computed value in the database when saving your model so you can filter on values requiring complex (or simple!) calculations.

Quick start

1. Install this library

   pip install django-computed-property
   

2. Add to INSTALLED_APPS

   INSTALLED_APPS = [
       ...,
       'computed_property'
   ]

3. Add a computed field to your model(s)

   from django.db import models
   import computed_property
   
   class MyModel(models.Model):
       doubled = computed_property.ComputedIntegerField(compute_from='double_it')
       base = models.IntegerField()
    
       def double_it(self):
           return self.base * 2

Documentation available at http://django-computed-property.readthedocs.io/en/latest/