fix

submission/views/admin.py

@@ -77,6 +77,8 @@ class SubmissionStatisticsAPI(APIView):
                 item["correct_rate"] = f"{rate}%"
                 accepted.append(item)
         
+        unaccepted = []
+        if person_count:
             unaccepted = list(set(all_persions) - set([item['username'] for item in accepted]))
         
         # 统计人数完成率