Welcome to django-computed-property!

Computed Property fields for Django models, inspired by Google Cloud NDB


django-computed-property supports Django 1.8 - 2.0 on Python 2.7, 3.4, 3.5, 3.6, pypy, and pypy3.

Only SQLite is tested, but any Django database backend should work.


django-computed-property is available on PyPI. Install it with:

pip install django-computed-property


Add computed_property to your list of INSTALLED_APPS in settings.py:


Then, simply import and use the included field classes in your models:

from django.db import models
from computed_property import ComputedTextField

class MyModel(models.Model):
    name = ComputedTextField(compute_from='calculation')

    def calculation(self):
        return 'some complicated stuff'

You can read values from the name field as usual, but you may not set the field’s value. When the field is accessed and when a model instance is saved, it will compute the field’s value using the provided callable (function/lambda), property name, or attribute name.

compute_from can be a reference to a function that takes a single argument (an instance of the model), or a string referring to a field, property, or other attribute on the instance.

Field types

Several other field classes are included: ComputedCharField, ComputedEmailField, ComputedIntegerField, ComputedDateField, ComputedDateTimeField, and others. All field classes accept the same arguments as their non-Computed versions.

To create an Computed version of some other field class, inherit from both ComputedField and the other field class:

from computed_property import ComputedField
from somewhere import MyField

class MyComputedField(ComputedField, MyField):


See the contributing docs.