PostgreSQL lookups and functions for Django apps

How often have you had the impression that Django was not providing all the lookup expressions and functions for your queries? Probably not that often, but now here is a small collection that I consider quite useful.

Installation

Just use:

pip install django-postgres-tweaks

As the title says it already, these tools are designed to be used in Django projects/apps. So make sure to add postgres_utils or postgres_utils.apps.PostgresUtilsConfig to the INSTALLED_APPS list in your project's settings.py!

That's it.

Usage

Lookups

The lookups provided by this package/app are automatically loaded when the app is installed. You can go ahead and just use them like Django's built-in lookups, e.g.:

Pizza.objects.filter(name__noregex="[ ]+")

Assume you have a model called Pizza with a name field.

Functions

Like the DB functions provided by Django, e.g. in django.db.models.functions, you need to need to import them prior to usage. An example query looks like this:

Topping.objects\
    .filter(name__contains="Onion")\
    .annotate(onion_color=RegexpReplace("name", " *Onion$", ""))\
    .values("name", "onion_color")\
    .order_by("name")