如何编写双条件while循环？我的多条件循环逻辑异常求助

问题现象 #

使用while type != "video" or type!= "audio":时循环无法正常终止，但单独用while type != "video":时功能正常。

错误原因 #

原条件逻辑存在矛盾：

• 输入video时，type != "audio"为真，整个or条件结果为真，循环持续执行
• 输入audio时，type != "video"为真，整个or条件结果为真，循环持续执行
• 输入任何值都会满足这个or条件，导致循环永远无法退出

修复方案 #

提供两种简洁的修复方式：

方式1：改用and逻辑 #

将or替换为and，表示既不是video也不是audio时才进入循环：

type = input("Do you want a video or an audio? (answer by video or audio)\n >> ")
while type != "video" and type != "audio":
    print('Error! select an existing type')
    type = input("Do you want a video or an audio? (answer by video or audio)\n >> ")
if type == "video":
    video_dwld()
elif type == "audio":
    audio_dwld()

方式2：用not in判断（更简洁易读） #

直接判断输入是否不在允许的选项列表中：

type = input("Do you want a video or an audio? (answer by video or audio)\n >> ")
while type not in ["video", "audio"]:
    print('Error! select an existing type')
    type = input("Do you want a video or an audio? (answer by video or audio)\n >> ")
if type == "video":
    video_dwld()
elif type == "audio":
    audio_dwld()

内容的提问来源于stack exchange，提问作者leoprosy