def _get_req_dataset_col_indexes(self, dataset_code, code_str):
        # ensure if column_index dict is specified, value is a list
        params = self._get_request_params(dataset_code)
        if 'column_index' != params:
            column_index = params['column_index']
            if not isinstance(column_index, list):
                raise ValueError(
                    Message.ERROR_COLUMN_INDEX_LIST % code_str)
            return column_index
        # default, no column indexes to filter
        return []
dataset/ETHPy150Open quandl/quandl-python/quandl/model/merged_dataset.py/MergedDataset._get_req_dataset_col_indexes/operator `in` -> `!=`