def difference(self, other):
        result_ranges = []
        result_cidrs = {}

        own_nets = sorted(self._cidrs)
        other_nets = sorted(other._cidrs)
        own_idx = 0
        other_idx = 0
        own_len = len(own_nets)
        other_len = len(other_nets)
        while own_idx < own_len and other_idx < other_len:
            own_cur = own_nets[own_idx]
            other_cur = other_nets[other_idx]

            if own_cur == other_cur:
                own_idx += 1
                other_idx += 1
            elif own_cur in other_cur:
                own_idx += 1
            elif other_cur in own_cur:
                other_idx = _subtract(own_cur, other_nets, other_idx,
                                      result_ranges)
                own_idx += 1
            else:
                # own_cur and other_cur have nothing in common
                if own_cur < other_cur:
                    result_cidrs[own_cur] = True
                    own_idx += 1
                else:
                    other_idx += 1

        # If the above loop terminated because it processed all cidrs of
        # "other", then any remaining cidrs in self must be part of the result.
        while own_idx < own_len:
            result_cidrs[own_nets[own_idx]] = True
            own_idx += 1

        for start, stop in _iter_merged_ranges(result_ranges):
            for cidr in iprange_to_cidrs(start, stop):
                result_cidrs[cidr] = True

        result = IPSet()
        result._cidrs = result_cidrs
        return result
:param other: an IP set.
dataset/ETHPy150Open drkjam/netaddr/netaddr/ip/sets.py/IPSet.difference