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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(self):
 """convenience method to just get one value or tuple of values for the query"""

        field_vals = None
        field_names = self.fields_select.names()
        fcount = len(field_names)
        if fcount:
            d = self._query('get_one')
            if d:
                field_vals = [d.get(fn, None) for fn in field_names]
                if fcount == 1:
                    field_vals = field_vals[0]

        else:
            raise ValueError("no select fields were set, so cannot return value")

        return field_vals