Django URLS, how to map root to app?

I know that this question was asked 2 years ago, but I’ve faced the same problem and found a solution:

In the project urls.py:

urlpatterns = patterns('',
    url(r'^', include('my_app.urls')), #NOTE: without $
)

In my_app.urls.py:

urlpatterns = patterns('',
    url(r'^$', 'my_app.views.home', name="home"),
    url(r'^v1/$', 'my_app.views.v1', name="name_1"),
    url(r'^v2/$', 'my_app.views.v2', name="name_2"),
    url(r'^v3/$', 'my_app.views.v3', name="name_3"),
)