def _filter_observables_by_time(
        self, df: pd.DataFrame, column: str
    ) -> pd.DataFrame:
        """Filter a dataframe by comparing the datetime in a column to the last run time.

        Args:
            df: The dataframe to filter.
            column: The column containing the datetime to compare.

        Returns:
            A filtered dataframe.
        """
        if self.last_run:
            logging.debug(f"Filtering {len(df)} observables by time.")
            logging.debug(f"Last run: {self.last_run}")
            logging.debug(f"Column: {column}")
            df = df[df[column] > np.datetime64(self.last_run)]
        return df
Filter a dataframe by comparing the datetime in a column to the last run time.

        Args:
            df: The dataframe to filter.
            column: The column containing the datetime to compare.

        Returns:
            A filtered dataframe.
        
core/schemas/task.py