我想让第二次写入时在原文件的末尾开始写如何修改代码：def apk_add_filefile_path apk_file_path apk_file_name try if public_functionis_file_existfile_path and public_functionis_file_existapk_file_path zf = zip

你可以修改代码，将文件的写入模式从"a"更改为"w"，这样就可以在原文件的末尾开始写入了。修改后的代码如下：

def apk_add_file(file_path, apk_file_path, apk_file_name):
    try:
        if public_function.is_file_exist(file_path) and public_function.is_file_exist(apk_file_path):
            zf = zipfile.ZipFile(apk_file_path, "w", zipfile.ZIP_DEFLATED)
            name_list = zf.namelist()
            if apk_file_name in name_list:
                zf.close()
                apk_delete_file(apk_file_path, apk_file_name)
                zf = zipfile.ZipFile(apk_file_path, "w", zipfile.ZIP_DEFLATED)
                zf.write(file_path, apk_file_name)
                zf.close()
            else:
                zf.write(file_path, apk_file_name)
                zf.close()
            return True
        else:
            logging.error(
                "the " + file_path + " or " + apk_file_path + " does not exist!")
            return False
    except IOError:
        return False

请注意，在将写入模式更改为"w"后，将会覆盖原文件的内容，因此在写入之前，你可能需要备份原文件