def get_summation(self):
        """Returns the summary value for the data in this column if a
        valid summation method is specified for it. Otherwise returns ``None``.
        """
        if self.summation not in self.summation_methods:
            return None

        summation_function = self.summation_methods[self.summation]
        data = [self.get_raw_data(datum) for datum in self.table.data]
        data = filter(lambda datum: datum is not None, data)

        if len(data):
            try:
                summation = summation_function(data)
                for filter_func in self.filters:
                    summation = filter_func(summation)
                return summation
            except __HOLE__:
                pass
        return None
dataset/ETHPy150Open CiscoSystems/avos/horizon/tables/base.py/Column.get_summation