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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def default_bitcoind_opts(config_file=None, prefix=False):
 """ Get our default bitcoind options, such as from a config file, or from sane defaults """


    default_bitcoin_opts = virtualchain.get_bitcoind_config(config_file=config_file)

    # drop dict values that are None
    default_bitcoin_opts = {k: v for k, v in default_bitcoin_opts.items() if v is not None}

    # strip 'bitcoind_'
    if not prefix:
        default_bitcoin_opts = opt_strip('bitcoind_', default_bitcoin_opts)

    return default_bitcoin_opts