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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 _check_args(args):
 """ check arguments before starting analysis. """

    logger.info("Checking parameters and files")
    args.dir_out = args.out
    args.samplename = "pro"
    global decision_cluster
    global similar
    if not os.path.isdir(args.out):
        logger.warning("the output folder doens't exists")
        os.mkdirs(args.out)
    if args.bed and args.gtf:
        logger.error("cannot provide -b and -g at the same time")
        raise SyntaxError
    if args.debug:
        logger.info("DEBUG messages will be showed in file.")
    if args.bed:
        args.list_files = args.bed
        args.type_ann = "bed"
    if args.gtf:
        args.list_files = args.gtf
        args.type_ann = "gtf"
    logger.info("Output dir will be: %s" % args.dir_out)
    if not all([file_exists(args.ffile), file_exists(args.afile)]):
        logger.error("I/O error: Seqs.ma or Seqs.bam. ")
        raise IOError("Seqs.ma or/and Seqs.bam doesn't exists.")
    if hasattr(args, 'list_files'):
        beds = args.list_files.split(",")
        for filebed in beds:
            if not file_exists(filebed):
                logger.error("I/O error: {0}".format(filebed))
                raise IOError("%s  annotation files doesn't exist" % filebed)
    param.decision_cluster = args.method
    if args.similar:
        param.similar = float(args.similar)
    if args.min_seqs:
        param.min_seqs = int(args.min_seqs)
    return args