changed grader to return 0 or 1

server/data_analysis_env.py

@@ -270,7 +270,8 @@ class DataAnalysisEnv(Environment):
             )
 
         self._state.answer_submitted = True
-        score = self._task.grade(action.answer)
+        raw_score = self._task.grade(action.answer)
+        score = max(0.01, min(0.99, raw_score))
         self._state.final_score = score
 
         return DataObservation(