Django official documentation and other tutorials on the web always use a trailing slash at the end of url. ex:

url(r'^accounts/login/', views.login)  # login view in turn calls login.html

# instead of

url(r'^accounts/login', views.login)

Since accounts is the directory and login (login.html) is the file, shouldn't we be using second url? This will also make GET parameters look more structured:

accounts/login?name='abc'  # login is a file that is accepting parameters
vs.
accounts/login/?name='abc' # login directory (maybe index) is accepting parameters??

One of Django’s core design philosophies is URLs should be beautiful.

So some url like accounts/detail?name='abc' should be mapped as accounts/detail/abc/. You can capture it using regex at your url configurations. Here the URL is pretty neat and user friendly. This will help the search engines to index your pages correctly (now you can forget about rel=canonical) and will help in seo.

Now the reason for a trailing slash, consider a view (in any framework) which relatively resolves about.html for a user at path, users/awesomeUser

since users/awesomeUser and users/awesomeUser/ are different,

1. If the user is at users/awesomeUser, the browser will resolve it as users/about.html because there ain't a trailing slash which we don't want

2. If the user is at users/awesomeUser/, the browser will resolve it as users/awesomeUser/about.html because there is a trailing slash

• child relative to family/parent/ is family/parent/child.
• child relative to family/parent is family/child.

Django Design philosophy on Definitive URLs reads,

Technically, foo.com/bar and foo.com/bar/ are two different URLs, and search-engine robots (and some Web traffic-analyzing tools) would treat them as separate pages. Django should make an effort to “normalize” URLs so that search-engine robots don’t get confused.

This is the reasoning behind the APPEND_SLASH setting. (APPEND_SLASH lets you force append slashes to a URL)

Still not convinced?

1. Since django observes both the urls as different, if you are caching your app, Django will keep two copies for same page at user/awesomeUser and user/awesomeUser/.
2. You gotta have issues with HTTP methods other than GET if you don't append slash to a URL (If you ever plan to build a REST API).

Update

You can't make POST/PUT/PATCH/DELETE methods to work with rest_framework unless you explicitly define APPEND_SLASH=False in settings and trailing_slash=False for each and every router you gotta use(if you use Routers). It is like you basically gonna skip this most times and you gotta waste a hell lot of time debugging this. Django recommends append slashes and doesn't force it.

Its up to the developer to append slashes or not.