add class pk

class_pk/urls/__init__.py

@@ -0,0 +1,2 @@
+# 空文件
+

class_pk/urls/oj.py

@@ -0,0 +1,10 @@
+from django.urls import path
+
+from ..views.oj import ClassRankAPI, UserClassRankAPI, ClassPKAPI
+
+urlpatterns = [
+    path("class_rank", ClassRankAPI.as_view()),
+    path("user_class_rank", UserClassRankAPI.as_view()),
+    path("class_pk", ClassPKAPI.as_view()),
+]
+