python怎么给文件逐行添加内容

with open("aa.txt", "w", encoding="utf-8") as f1:

    with open("ap.txt", "r+", encoding="utf-8") as f:

        data = f.readlines()   

    for line in data:

        lis = line.strip()+"\n"+"radio 2\nchannel\n"

        f1.writelines(lis)