python_deep_copy.py

import copy
a = set([hashabledict({1:11}), hashabledict({2:22})])
b = set([hashabledict({1:11}), hashabledict({3:33})])
for i in range(3):
    print "set a:", a
    delta = a-b
    print "delta", delta
    for item in copy.deepcopy(delta):
        print id(item)
        item[1] = "xx"
    print "*"*10
    
#--------------result-----------------
#set a: set([{1: 11}, {2: 22}])
#delta set([{2: 22}])
#72099512
#**********
#set a: set([{1: 11}, {2: 22}])
#delta set([{2: 22}])
#72098600
#**********
#set a: set([{1: 11}, {2: 22}])
#delta set([{2: 22}])
#72099512
#**********