# Django 1.8.18.dev20170123152445 documentation

# `django.conf.urls` utility functions

## patterns()

`patterns`(prefix, pattern_description, ...)

Deprecated since version 1.8: `urlpatterns` should be a plain list of `django.conf.urls.url()` instances instead.

A function that takes a prefix, and an arbitrary number of URL patterns, and returns a list of URL patterns in the format Django needs.

The first argument to `patterns()` is a string `prefix`. Here’s the example URLconf from the Django overview:

    from django.conf.urls import patterns, url

    urlpatterns = patterns('',
        url(r'^articles/([0-9]{4})/$', 'news.views.year_archive'),
        url(r'^articles/([0-9]{4})/([0-9]{2})/$', 'news.views.month_archive'),
        url(r'^articles/([0-9]{4})/([0-9]{2})/([0-9]+)/$', 'news.views.article_detail'),
    )

In this example, each view has a common prefix – `'news.views'`. Instead of typing that out for each entry in `urlpatterns`, you can use the first argument to the `patterns()` function to specify a prefix to apply to each view function.

With this in mind, the above example can be written more concisely as:

    from django.conf.urls import patterns, url

    urlpatterns = patterns('news.views',
        url(r'^articles/([0-9]{4})/$', 'year_archive'),
        url(r'^articles/([0-9]{4})/([0-9]{2})/$', 'month_archive'),
        url(r'^articles/([0-9]{4})/([0-9]{2})/([0-9]+)/$', 'article_detail'),
    )

Note that you don’t put a trailing dot (`"."`) in the prefix. Django puts that in automatically.

The remaining arguments should be tuples in this format:

    (regular expression, Python callback function [, optional_dictionary [, optional_name]])

The `optional_dictionary` and `optional_name` parameters are described in Passing extra options to view functions.

Note

Because `patterns()` is a function call, it accepts a maximum of 255 arguments (URL patterns, in this case). This is a limit for all Python function calls. This is rarely a problem in practice, because you’ll typically structure your URL patterns modularly by using `include()` sections. However, on the off-chance you do hit the 255-argument limit, realize that `patterns()` returns a Python list, so you can split up the construction of the list.

    urlpatterns = patterns('',
        ...
        )
    urlpatterns += patterns('',
        ...
        )

Python lists have unlimited size, so there’s no limit to how many URL patterns you can construct. The only limit is that you can only create 254 at a time (the 255th argument is the initial prefix argument).

## static()

`static.``static`(prefix, view=django.views.static.serve, **kwargs)

Helper function to return a URL pattern for serving files in debug mode:

    from django.conf import settings
    from django.conf.urls.static import static

    urlpatterns = [
        # ... the rest of your URLconf goes here ...
    ] + static(settings.MEDIA_URL, document_root=settings.MEDIA_ROOT)

The `view` argument changed from a string (`'django.views.static.serve'`) to the function.

## url()

`url`(regex, view, kwargs=None, name=None, prefix='')

`urlpatterns` should be a list of `url()` instances. For example:

    urlpatterns = [
        url(r'^index/$', index_view, name="main-view"),
        ...
    ]

This function takes five arguments, most of which are optional:

    url(regex, view, kwargs=None, name=None, prefix='')

The `kwargs` parameter allows you to pass additional arguments to the view function or method. See Passing extra options to view functions for an example.

See Naming URL patterns for why the `name` parameter is useful.

Deprecated since version 1.8: Support for string `view` arguments is deprecated and will be removed in Django 1.10. Pass the callable instead.

The `prefix` parameter has the same meaning as the first argument to `patterns()` and is only relevant when you’re passing a string as the `view` parameter.

## include()

`include`(module, namespace=None, app_name=None)
`include`(pattern_list)
`include`((pattern_list, app_namespace, instance_namespace))

  A function that takes a full Python import path to another URLconf module that should be “included” in this place. Optionally, the application namespace and instance namespace where the entries will be included into can also be specified.

  `include()` also accepts as an argument either an iterable that returns URL patterns or a 3-tuple containing such iterable plus the names of the application and instance namespaces.

  Parameters: | module – URLconf module (or module name) namespace (string) – Instance namespace for the URL entries being included app_name (string) – Application namespace for the URL entries being included pattern_list – Iterable of `django.conf.urls.url()` instances app_namespace (string) – Application namespace for the URL entries being included instance_namespace (string) – Instance namespace for the URL entries being included

See Including other URLconfs and URL namespaces and included URLconfs.

## handler400

`handler400`

A callable, or a string representing the full Python import path to the view that should be called if the HTTP client has sent a request that caused an error condition and a response with a status code of 400.

By default, this is `'django.views.defaults.bad_request'`. That default value should suffice.

See the documentation about the 400 (bad request) view for more information.

## handler403

`handler403`

A callable, or a string representing the full Python import path to the view that should be called if the user doesn’t have the permissions required to access a resource.

By default, this is `'django.views.defaults.permission_denied'`. That default value should suffice.

See the documentation about the 403 (HTTP Forbidden) view for more information.

## handler404

`handler404`

A callable, or a string representing the full Python import path to the view that should be called if none of the URL patterns match.

By default, this is `'django.views.defaults.page_not_found'`. That default value should suffice.

See the documentation about the 404 (HTTP Not Found) view for more information.

## handler500

`handler500`

A callable, or a string representing the full Python import path to the view that should be called in case of server errors. Server errors happen when you have runtime errors in view code.

By default, this is `'django.views.defaults.server_error'`. That default value should suffice.

See the documentation about the 500 (HTTP Internal Server Error) view for more information.