import cPickle


import pickletools

protocol = 2

for protocol in range(3):

    print "Protocol", protocol, ":"

    real_const = { "modules" : None }
    dump1 = cPickle.dumps( real_const, protocol=protocol )
    loaded_const = cPickle.loads( dump1 )

    assert real_const == loaded_const
    dump2 = cPickle.dumps( loaded_const, protocol=protocol )
    loaded_const = cPickle.loads( dump2 )
    assert real_const == loaded_const


    dump3 = cPickle.dumps( loaded_const, protocol=protocol )
    loaded_const = cPickle.loads( dump3 )
    assert real_const == loaded_const

    print "Dumping read const const stream", repr( dump1 )
    pickletools.dis( dump1 )
    print "Dumping load const const stream", repr( dump2 )
    pickletools.dis( dump2 )
    print "Dumping load const const stream", repr( dump3 )
    pickletools.dis( dump3 )