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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 _get_label(self, axis):
 """Return plot label for column for the given axis."""


        if axis == 'x':
            colname = self.x_col
        else:  # y
            colname = self.y_col

        if colname == self._idxname:
            label = 'Index'
        else:
            col = self.tab[colname]
            if col.unit:
                label = '{0} ({1})'.format(col.name, col.unit)
            else:
                label = col.name

        return label