format code

problem/tests.py

@@ -6,6 +6,7 @@ from zipfile import ZipFile
 from django.conf import settings
 
 from utils.api.tests import APITestCase
+
 from .models import ProblemTag
 from .views.admin import TestCaseUploadAPI
 

problem/urls/admin.py

@@ -1,6 +1,6 @@
 from django.conf.urls import url
 
-from ..views.admin import ProblemAPI, TestCaseUploadAPI, ContestProblemAPI
+from ..views.admin import ContestProblemAPI, ProblemAPI, TestCaseUploadAPI
 
 urlpatterns = [
     url(r"^test_case/upload/?$", TestCaseUploadAPI.as_view(), name="test_case_upload_api"),

problem/views/admin.py

@@ -10,9 +10,10 @@ from contest.models import Contest
 from utils.api import APIView, CSRFExemptAPIView, validate_serializer
 from utils.shortcuts import rand_str
 
-from ..models import Problem, ProblemRuleType, ProblemTag, ContestProblem
-from ..serializers import (CreateProblemSerializer, EditProblemSerializer,
-                           ProblemSerializer, TestCaseUploadForm, CreateContestProblemSerializer)
+from ..models import ContestProblem, Problem, ProblemRuleType, ProblemTag
+from ..serializers import (CreateContestProblemSerializer,
+                           CreateProblemSerializer, EditProblemSerializer,
+                           ProblemSerializer, TestCaseUploadForm)
 
 
 class TestCaseUploadAPI(CSRFExemptAPIView):