方法一:stus=["哈巴狗","小马","小黑"]username=input("user:")count=stus.count(username)if count>0: print("该用户已经存在")方法二:
stus=["哈巴狗","小马","小黑"]username=input("user:")
if username in stus:#在列表里面 not in 不在列表里面 print("该用户已经存在")
posted on 2018-07-31 14:57 smileBB 阅读(503) 评论(0) 编辑 收藏 举报