# Copyright (c) 2011 Edward Langley
# All rights reserved.
# 
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
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# Redistributions of source code must retain the above copyright notice,
# this list of conditions and the following disclaimer.
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# Redistributions in binary form must reproduce the above copyright
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def cmp_dicts(dct, dct1):
    cp = set()
    for k in dct.keys():
        if dct[k] != dct1.get(k,None):
            cp.add(k)
    return cp