#!/usr/bin/env python

class DictDiffer(object):

"""

Calculate the difference between two dictionaries as:

(1) items added

(2) items removed

(3) keys same in both but changed values

(4) keys same in both and unchanged values

"""

def __init__(self, current_dict, past_dict):

self.current_dict = current_dict

self.past_dict = past_dict

self.set_current = set(current_dict.keys())

self.set_past = set(past_dict.keys())

self.intersect = self.set_current.intersection(self.set_past)

def added(self):

return self.set_current - self.intersect

def removed(self):

return self.set_past - self.intersect

def changed(self):

return (set(o for o in self.intersect

if self.past_dict[o] != self.current_dict[o]))

def unchanged(self):

return (set(o for o in self.intersect

if self.past_dict[o] == self.current_dict[o]))

class NmapDiff(DictDiffer):

def __init__(self, nmap_obj1, nmap_obj2):

if nmap_obj1.id != nmap_obj2.id:

raise NmapDiffException("Comparing objects with non-matching id")

self.object1 = nmap_obj1.get_dict()

self.object2 = nmap_obj2.get_dict()

DictDiffer.__init__(self, self.object1, self.object2)

def __repr__(self):

return ('added: [{0}] -- changed: [{1}] -- \

unchanged: [{2}] -- removed [{3}]'.format(self.added(),

self.changed(),

self.unchanged(),

self.removed()))

class NmapDiffException(Exception):

def __init__(self, msg):

self.msg = msg