def paste_columns(line, sep=" "):
    """
    Create GFF/GTF line from read_gff_line
    """
    cols = line.columns
    attr = line.attributes
    attr_paste = "; ".join(
        "%s%s%s" % (a, sep, attr[a]) for a in attr)
    return "\t".join([cols['chrom'], cols['source'], cols['type'],
                      cols['start'], cols['end'], cols['score'],
                      cols['strand'], cols['ext'], attr_paste])