def _processed_columns(self) -> List[str]:
        """
        Get the list of processed data columns, excluding any dicts with callable values
        """
        return [
            list(col.keys())[0] if isinstance(col, dict) else col
            for col in self._columns[self._first_met_col :]
        ]

        Get the list of processed data columns, excluding any dicts with callable values
        
meteostat/interface/meteodata.py