def update_session(fname=None):
    """Update current Scapy session from the file specified in the fname arg.

    params:
     - fname: file to load the scapy session from"""
    if fname is None:
        fname = conf.session
    try:
        s = six.moves.cPickle.load(gzip.open(fname, "rb"))
    except IOError:
        s = six.moves.cPickle.load(open(fname, "rb"))
    scapy_session = six.moves.builtins.__dict__["scapy_session"]
    scapy_session.update(s)
    update_ipython_session(scapy_session)