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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def yieldOutput(self):
 """ Generate the text output for the table. @rtype: generator of str @return: Text output. """

        width = self.__width
        if width:
            num_cols = len(width)
            fmt = ['%%%ds' % -w for w in width]
            if width[-1] > 0:
                fmt[-1] = '%s'
            fmt = self.__sep.join(fmt)
            for row in self.__cols:
                row.extend( [''] * (num_cols - len(row)) )
                yield fmt % tuple(row)