python改变字幕时间线

#处理小时，和分钟字母串
def myHandle(she):
    kaishi_shi = she
    if len(str(kaishi_shi)) < 2:
        kaishi_shi_str = "0%s" % str(kaishi_shi)
    else:
        kaishi_shi_str = str(kaishi_shi)
    print(kaishi_shi_str)
    return kaishi_shi_str

#处理开始时间字符串
#开始时间串为，如，00:59:59,300
def myHandelKaiShi(kaishishijianchuan):
    fir_list_one_list = kaishishijianchuan.split(":")
    print(fir_list_one_list)
    kaishi_shi_fen = int(fir_list_one_list[0]) * 60 + int(fir_list_one_list[1]) - 39
    kaishi_shi = int(kaishi_shi_fen / 60)
    print(kaishi_shi)
    kaishi_fen = int(kaishi_shi_fen % 60)
    print(kaishi_fen)
    print("再次拼接")
    kaishi_shi_str = myHandle(kaishi_shi)  # 处理时
    kaishi_fen_str = myHandle(kaishi_fen)  # 处理分
    new_kaishi_shijian_str = "%s:%s:%s" % (kaishi_shi_str,
                                           kaishi_fen_str,
                                           fir_list_one_list[2])
    print(new_kaishi_shijian_str)
    return new_kaishi_shijian_str

#处理结束时间字符串
#结束时间串为，如， 00:39:57,360
def myHandelJieShu(jieshushijianchuan):
    kaishishijianchuan = jieshushijianchuan
    fir_list_one_list = kaishishijianchuan.split(":")
    print(fir_list_one_list)
    kaishi_shi_fen = int(fir_list_one_list[0]) * 60 + int(fir_list_one_list[1]) - 39
    kaishi_shi = int(kaishi_shi_fen / 60)
    print(kaishi_shi)
    kaishi_fen = int(kaishi_shi_fen % 60)
    print(kaishi_fen)
    print("再次拼接")
    kaishi_shi_str = myHandle(kaishi_shi)  # 处理时
    kaishi_fen_str = myHandle(kaishi_fen)  # 处理分
    new_kaishi_shijian_str = " %s:%s:%s" % (kaishi_shi_str,
                                           kaishi_fen_str,
                                           fir_list_one_list[2])
    print(new_kaishi_shijian_str)
    new_jieshu_shijian_str = new_kaishi_shijian_str
    return new_jieshu_shijian_str



with open(r'zhong-3.srt' , 'r', encoding='utf-8') as f:
    read_list = f.readlines()
    print(read_list)

for one in read_list:
    xietu_content =''
    one_qudiao = one.strip("\n")
    if "-->" in one:
        fir_list = one.split("-->")
        print(fir_list)
        kaishishijianchuan = fir_list[0]
        new_kaishishijianchuan = myHandelKaiShi(kaishishijianchuan)
        jieshushijianchuan = fir_list[1]
        new_jieshushijianchuan = myHandelJieShu(jieshushijianchuan)
        new_content = "%s-->%s" %(new_kaishishijianchuan,new_jieshushijianchuan)
        print("new_content:")
        print(new_content)
        xietu_content = new_content

    else:
        if one_qudiao.isdigit():
            print("%s去掉换行后仅是数字")
            xietu_content = "\n"+str(int(one)-399)+"\n"
        else:
            xietu_content = one

    with open(r'xin.srt', 'a+', encoding='utf-8') as f:
        read_list = f.write(xietu_content)