models.py 文件源码

def export(self, file_handle=None):
        '''
        exports the task questions and answers as a CSV
        '''
        try:
            if not file_handle:
                file_handle = StringIO.StringIO()
            data = self.task.answers
            # http://stackoverflow.com/a/11399424
            # getting the union of all keys in all of the answer rows
            headers = list(set().union(*(i.keys() for i in data)))
            writer = csv.DictWriter(file_handle, fieldnames=headers)
            writer.writeheader()
            for row in data:
                writer.writerow(row)
            export_file = ContentFile(file_handle.getvalue())
            export_filename = "ST_TASK_{task_id}_EXPORT_{date}.csv".format(task_id=self.task.id,
                                                                           date=str(datetime.date.today()))
            self.export_file.save(name=export_filename, content=export_file, save=False)
            self.status = self.SUCCESS
        except Exception as e:
            LOG.exception(e)
            self.status = self.FAILURE
        self.save()