def getExInfo(self):
        if(self.extype is not "topicmodel"):
            return TopicModelEx.query.filter_by(ex_id=self.id).first()
        elif(self.extype == "summarize"):
            return SummarizeEx.query.filter_by(ex_id=self.id).first()
        else:
            return None
dataset/ETHPy150Open daeilkim/refinery/refinery/refinery/data/models.py/Experiment.getExInfo/operator `==` -> `is not`