I noticed that in Django there are two formats of urlpatterns in file urls.py:
urlpatterns = [
url(...),
url(...),
]
and
urlpatterns = pattern('',
url(...),
url(...),
)
The first is a list of url instances, and the second invokes the pattern module with an empty string and a number of url instances as parameters.
In Django 1.8+, urlpatterns should simply be a list of url()s. This new syntax actually works in 1.7 as well.
urlpatterns = [
url(...),
url(...),
]
The old syntax using pattern is deprecated in Django 1.8, and is removed in Django 1.10.
urlpatterns = pattern('',
url(...),
url(...),
)
With the old syntax, you could provide a prefix. The example given in the docs is
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]+)/$', 'article_detail'),
)
However, using strings arguments for the view is now deprecated as well, and you should provide the callable instead.
Per the documentation, patterns is:
A function that takes a prefix, and an arbitrary number of URL patterns, and returns a list of URL patterns in the format Django needs.
The first argument to
patterns()is a stringprefix.
It also provides an example of why you might want to use it:
from django.conf.urls import patterns, url urlpatterns = patterns('', url(r'^articles/([0-9]{4})/$', '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 inurlpatterns, you can use the first argument to thepatterns()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'), )
However, note that this function is deprecated:
Deprecated since version 1.8:
urlpatternsshould be a plain list ofdjango.conf.urls.url()instances instead.
Note that the explanation as to why includes (with good reason, clearly!):
Thus
patterns()serves little purpose and is a burden when teaching new users (answering the newbie’s question "why do I need this empty string as the first argument topatterns()?").
patterns() function are deprecated and will be removed in Django 1.10. To avoid deprecation warnings, use a plain list instead.