如何终止Python中loop_of_user函数关联的while循环？

我需要终止while循环，尝试使用status语句实现但未成功，想了解终止while循环的最简单方法。以下是我的代码：

def loop_of_user(my_details):
    """_summary_
    the function do a variety of actions on the the variable my_detailes
        :my_details (dict): dictionary of detailes on mariha
    """
    num = int(input())
    if num == 1:
        print(my_details["first_name"])
    elif num == 2:
        print(my_details["birth_date"][3:5])
    elif num == 3:
        print(len(my_details["hobbies"]))
    elif num == 4:
        print(my_details["hobbies"][-1])
    elif num == 5:
        my_details["hobbies"].append("cooking")
        print(my_details["hobbies"])
    elif num == 6:
        print(tuple_birth_date(my_details["birth_date"]))
    elif num == 7:
        my_details ["age"] = calculate_age(my_details["birth_date"])
        print(my_details["age"])
    else:
        return "break"
        

def main():
    mariah_details = {"first_name" : "mariah", "last_name" : "carey", "birth_date" : "27.03.1970", "hobbies" : ["sing", "compose", "act"]}
    status = ""
    while status != "break":
        loop_of_user(mariah_details)

if __name__ == "__main__":
   main()  

我尝试通过status变量和else分支返回"break"来终止循环，但循环仍持续执行，希望得到帮助。

问题原因 #

你的代码中，loop_of_user函数确实返回了"break"，但你没有把这个返回值赋值给status变量，导致status始终是空字符串，循环条件status != "break"永远成立，循环无法终止。

最简单的两种解决方法 #

方法1：修复原有status变量方案 #

只需要在调用函数时，将返回值赋值给status即可：

def main():
    mariah_details = {"first_name" : "mariah", "last_name" : "carey", "birth_date" : "27.03.1970", "hobbies" : ["sing", "compose", "act"]}
    status = ""
    while status != "break":
        status = loop_of_user(mariah_details)  # 接收函数返回值，更新status

方法2：直接使用break语句（更简洁） #

不需要额外的status变量，直接在循环内部判断终止条件，用break跳出循环。可以调整函数返回布尔值来控制循环：

def loop_of_user(my_details):
    num = int(input())
    if num == 1:
        print(my_details["first_name"])
    elif num == 2:
        print(my_details["birth_date"][3:5])
    elif num == 3:
        print(len(my_details["hobbies"]))
    elif num == 4:
        print(my_details["hobbies"][-1])
    elif num == 5:
        my_details["hobbies"].append("cooking")
        print(my_details["hobbies"])
    elif num == 6:
        print(tuple_birth_date(my_details["birth_date"]))
    elif num == 7:
        my_details ["age"] = calculate_age(my_details["birth_date"])
        print(my_details["age"])
    else:
        return True  # 返回True表示需要终止循环
    return False  # 返回False继续循环

def main():
    mariah_details = {"first_name" : "mariah", "last_name" : "carey", "birth_date" : "27.03.1970", "hobbies" : ["sing", "compose", "act"]}
    while True:
        if loop_of_user(mariah_details):
            break  # 满足终止条件直接跳出循环

如果想更简化，也可以把输入逻辑直接放到main函数里，省去函数返回值的处理：

def main():
    mariah_details = {"first_name" : "mariah", "last_name" : "carey", "birth_date" : "27.03.1970", "hobbies" : ["sing", "compose", "act"]}
    while True:
        num = int(input())
        if num == 1:
            print(mariah_details["first_name"])
        elif num == 2:
            print(mariah_details["birth_date"][3:5])
        elif num == 3:
            print(len(mariah_details["hobbies"]))
        elif num == 4:
            print(mariah_details["hobbies"][-1])
        elif num == 5:
            mariah_details["hobbies"].append("cooking")
            print(mariah_details["hobbies"])
        elif num == 6:
            print(tuple_birth_date(mariah_details["birth_date"]))
        elif num == 7:
            mariah_details ["age"] = calculate_age(mariah_details["birth_date"])
            print(mariah_details["age"])
        else:
            break  # 输入非指定数字，直接终止循环

内容的提问来源于stack exchange，提问作者user20315313