Define the options from default.conf dynamically

def define_options(default_conf):
    """
    Define the options from default.conf dynamically
    """
    default = {}
    with open(default_conf, 'rb') as f:
        exec_in(native_str(f.read()), {}, default)

    for name, value in default.iteritems():
        # if the option is already defined by tornado
        # override the value
        # a list of options set by tornado:
        # log_file_num_backups, logging, help,
        # log_to_stderr, log_file_max_size, log_file_prefix
        if name in options:
            setattr(options, name, value)
        # otherwise define the option
        else:
            define(name, value)