remove voided questions

oab_exams_no_train.py

@@ -39,6 +39,7 @@ class OABExamsNoTrain(datasets.GeneratorBasedBuilder):
                     "exam_id": datasets.Value("string"),
                     "exam_year": datasets.Value("string"),
                     "question_type": datasets.Value("string"),
+                    "nullified": datasets.Value("bool"),
                     "question": datasets.Value("string"),
                     "choices": datasets.Sequence(feature={
                         "text": datasets.Value("string"),
@@ -53,6 +54,9 @@ class OABExamsNoTrain(datasets.GeneratorBasedBuilder):
 
     def _split_generators(self, dl_manager):
         dataset = datasets.load_dataset(_URL, split="train")
+        #remove voided questions
+        dataset = dataset.filter(lambda example: not example['nullified'])
+
         dataset_dev = dataset.filter(lambda example: example['exam_id'] in _EXAM_IDS_DEV)
         dataset_test = dataset.filter(lambda example: example['exam_id'] not in _EXAM_IDS_DEV)