Many-to-many relationships Many-to-one relationships One-to-one relationships

Django ships with a variety of extra, optional tools that solve common problems (contrib.*). For easier maintenance and to trim the size of the codebase, a few of those applications have been moved out to separate projects. Localflavor django-localflavor is a collection of utilities for particular countries and cultures. GitHub Documentation PyPI Comments django-contrib-comments can be used to attach comments to any model, so you can use it for comments on blog entries, photos, book chapters,

PostgreSQL has a number of features which are not shared by the other databases Django supports. This optional module contains model fields and form fields for a number of PostgreSQL specific data types. Psycopg2 2.5 or higher is required, though we highly recommend using the latest release. Some fields require higher versions. Note Django is, and will continue to be, a database-agnostic web framework. We would encourage those writing reusable applications for the Django community to write dat

A set of Django template filters useful for adding a “human touch” to data. To activate these filters, add 'django.contrib.humanize' to your INSTALLED_APPS setting. Once you’ve done that, use {% load humanize %} in a template, and you’ll have access to the following filters. apnumber For numbers 1-9, returns the number spelled out. Otherwise, returns the number. This follows Associated Press style. Examples: 1 becomes one. 2 becomes two. 10 becomes 10. You can pass in either an integer or

Django raises some of its own exceptions as well as standard Python exceptions. Django Core Exceptions Django core exception classes are defined in django.core.exceptions. AppRegistryNotReady exception AppRegistryNotReady [source] This exception is raised when attempting to use models before the app loading process, which initializes the ORM, is complete. ObjectDoesNotExist exception ObjectDoesNotExist [source] The base class for DoesNotExist exceptions; a try/except for ObjectDoesNotE

Signal.send_robust(sender, **kwargs) [source] To send a signal, call either Signal.send() (all built-in signals use this) or Signal.send_robust(). You must provide the sender argument (which is a class most of the time) and may provide as many other keyword arguments as you like. For example, here’s how sending our pizza_done signal might look: class PizzaStore(object): ... def send_pizza(self, toppings, size): pizza_done.send(sender=self.__class__, toppings=toppings, size=s

Because Django was developed in a fast-paced newsroom environment, it was designed to make common Web-development tasks fast and easy. Here’s an informal overview of how to write a database-driven Web app with Django. The goal of this document is to give you enough technical specifics to understand how Django works, but this isn’t intended to be a tutorial or reference – but we’ve got both! When you’re ready to start a project, you can start with the tutorial or dive right into more detailed do

class Signal(providing_args=list) [source] All signals are django.dispatch.Signal instances. The providing_args is a list of the names of arguments the signal will provide to listeners. This is purely documentational, however, as there is nothing that checks that the signal actually provides these arguments to its listeners. For example: import django.dispatch pizza_done = django.dispatch.Signal(providing_args=["toppings", "size"]) This declares a pizza_done signal that will provide receiv

Signal.connect(receiver, sender=None, weak=True, dispatch_uid=None) [source] Parameters: receiver – The callback function which will be connected to this signal. See Receiver functions for more information. sender – Specifies a particular sender to receive signals from. See Connecting to signals sent by specific senders for more information. weak – Django stores signal handlers as weak references by default. Thus, if your receiver is a local function, it may be garbage collected. To prev

Signal.send(sender, **kwargs) [source]