Function get_var

Get boolean input from user. If var_name is not set in env, ask user to enable query_item or not. If the response is empty, use the default. Args: environ_cp: copy of the os.environ. var_name: string for name of environment variable, e.g. "TF_NEED_HDFS". query_item: string for fe

(environ_cp,
            var_name,
            query_item,
            enabled_by_default,
            question=None,
            yes_reply=None,
            no_reply=None)