Get raster value by (row, col).

        Args:
            row: row number.
            col: col number.

        Returns:
            raster value, None if the input are invalid.

def get_value_by_row_col(self, row, col):
        """Get raster value by (row, col).

        Args:
            row: row number.
            col: col number.

        Returns:
            raster value, None if the input are invalid.
        """
        if row < 0 or row >= self.nRows or col < 0 or col >= self.nCols:
            raise ValueError("The row or col must be >=0 and less than "
                             "nRows (%d) or nCols (%d)!" % (self.nRows, self.nCols))
        else:
            value = self.data[int(round(row))][int(round(col))]
            if value == self.noDataValue:
                return None
            else:
                return value