  
  
  class TestUrlPatternTestCase(URLPatternsTestCase):
      urlpatterns = [
          url(r'^$', view),
      ]
  
      @classmethod
      def setUpClass(cls):
          assert urlpatterns is not cls.urlpatterns
 
</s> remove     url(r'^$', schema_view),
    url(r'^', include(router.urls))
 </s> add     path('', schema_view),
    path('', include(router.urls)) </s> remove             url(r'^example/?$', ExampleView.as_view()),
 </s> add             path('example/', ExampleView.as_view()), </s> remove     url(r'^view/$', view),
    url(r'^session-view/$', session_view),
    url(r'^redirect-view/$', redirect_view),
    url(r'^post-view/$', post_view)
 </s> add     path('view/', view),
    path('session-view/', session_view),
    path('redirect-view/', redirect_view),
    path('post-view/', post_view) </s> remove     url(r'^$', FooView.as_view())
 </s> add     path('', FooView.as_view()) </s> remove             url(r'^api/v1/example/?$', views.ExampleListView.as_view()),
            url(r'^api/v1/example/(?P<pk>\d+)/?$', views.ExampleDetailView.as_view()),
            url(r'^api/v1/example/(?P<pk>\d+)/sub/?$', views.ExampleDetailView.as_view()),
 </s> add             path('api/v1/example/', views.ExampleListView.as_view()),
            path('api/v1/example/<int:pk>/', views.ExampleDetailView.as_view()),
            path('api/v1/example/<int:pk>/sub/', views.ExampleDetailView.as_view()),
        path('', view),
  
  
  class TestUrlPatternTestCase(URLPatternsTestCase):
      urlpatterns = [
        path('', view),
      ]
  
      @classmethod
      def setUpClass(cls):
          assert urlpatterns is not cls.urlpatterns
keep keep keep keep replace keep keep keep keep keep
 Replace all url() calls with path() or re_path() (#7512)

* url() is deprecated in Django 3.1

* update given feedbacks on url() is deprecated in Django 3.1

* Fix test_urlpatterns.py to continue testing mixed re_path() and path()

* Fix one missed reference

Co-authored-by: sanjusci <sanju.sci9@gmail.com> 
tests/test_testing.py