空列表在while和for循环的上下文中不产生任何输出

Question

我写了这段代码来练习循环和嵌套条件。我最初的意图是创建两个空列表，这些空列表将通过附加已排序的输入来逐步填充。但是，当我将列表初始化为at_risk = []和safe = []时，没有任何输出。我做错了什么？当我在其中添加一个元素（引号或字符串）时，代码可以正常运行。

i = 10
at_risk = []
safe = []

while i > 0:
    for kids in at_risk:
        question = input("Have you ever been questioned by the police, Y/N? or Q to end: ").upper()
        name = input("What is your name? ")
        age = int(input("How old are you?"))
        if question =="Y":
            at_risk.append(name)
            print("This young kid", name, "is at risk.")
            if age < 15:
                print("These young kids", at_risk, "are at heightened risk.")
        elif question == "N":
            safe.append(name)
            print("This kid",name," is safe.")
            print("These kids",safe,"are safe.")
        else:
            if question == "Q":
                exit(0)

Answer 1

问题完全在以下代码行内：

at_risk = []
safe = []

while i > 0:
    for kids in at_risk:

您使用针对at_risk中的孩子]初始化循环，但是at_risk为空，因此它将永远不会开始循环。只需更改at_risk，它就可以工作！