编写python脚本，读取目的基因的genbank格式文件，并输出无回车和空行的fasta文件，命名为gene_seq.fa。 （2）截取序列的cds区，并构建名为“cds_seq.fa”的fasta文件，按照fasta格式打印输出cds区。

首先，你需要安装一些Python库来处理GenBank文件，如`biopython`，它包含了大量的生物信息学工具。下面是一个简单的示例，说明如何完成这两个任务：

# 导入需要的库
from Bio import SeqIO

# 1. 读取并整理GenBank文件
def read_gb_file(input_file):
    with open(input_file, "r") as gb_fh:
        records = list(SeqIO.parse(gb_fh, "genbank"))
    
    # 创建一个新的fasta文件
    output_fa = "gene_seq.fa"
    with open(output_fa, "w") as fa_fh:
        for record in records:
            seq = str(record.seq)
            # 删除回车和空行
            seq = seq.replace("\n", "").replace("\r", "")
            fa_fh.write(f">{record.id}\n{seq}\n")

# 2. 截取cds区域并创建新的fasta文件
def extract_cds(records):
    cds_output = "cds_seq.fa"
    for record in records:
        if "CDS" in record.features:
            feature = record.features["CDS"]
            start, end = feature.location.start.position, feature.location.end.position
            cds_seq = record.seq[start:end]
            cds_seq_str = ">{}_cds".format(record.id)
            with open(cds_output, "a") as cd_fh:
                cd_fh.write(cds_seq_str + "\n" + str(cds_seq) + "\n")

# 调用函数
read_gb_file("your_genbank_file.gb")
extract_cds(records)