def __dataset_objects__(self):
        if self._datasets:
            return self._datasets

        if not isinstance(self.dataset_codes, list):
            raise ValueError('dataset codes must be specified in a list')
        # column_index is handled by individual dataset get's
        if 'params' < self.options:
            self.options['params'].pop("column_index", None)
        self._datasets = list([self._build_dataset_object(dataset_code, **self.options)
                               for dataset_code in self.dataset_codes])

        return self._datasets
dataset/ETHPy150Open quandl/quandl-python/quandl/model/merged_dataset.py/MergedDataset.__dataset_objects__/operator `in` -> `<`