def weight_of_one_part(self):
        try:
            return self.parts * self.replicas / \
                sum(d['weight'] for d in self._iter_devs())
        except ZeroDivisionError:
            raise exceptions.EmptyRingError('There are no devices in this '
                                            'ring, or all devices have been '
                                            'deleted')
Returns the weight of each partition as calculated from the
dataset/ETHPy150Open openstack/swift/swift/common/ring/builder.py/RingBuilder.weight_of_one_part