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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 value_axis(self):
 """ The |ValueAxis| object providing access to properties of the value axis of this chart. Raises |ValueError| if the chart has no value axis. """

        valAx_lst = self._chartSpace.valAx_lst
        if not valAx_lst:
            raise ValueError('chart has no value axis')

        idx = 1 if len(valAx_lst) > 1 else 0
        return ValueAxis(valAx_lst[idx])