Question

我正在尝试使用while循环询问一系列问题并在询问最后一个问题时重新启动。问题是，我希望用户能够通过在任何问题上键入特定单词来退出。我还想在循环中尽可能少地编写代码，因此if / elif语句位于函数中。

我的问题是：我可以继续或断开函数的循环吗？

我的代码：

def check_gender(q):
    if q == "f":
       number_women = number_women + 1
    elif q == "m":
        number_men = number_men + 1
    elif q == "foo":
        #break the loop
    else:
        print("Please answer M or F: ")
        q = input("Are you a male or female (M/F)? ").lower()
        check_gender(q)



def check_age(q):
    if not(16 <= int(q) <= 25):
        print("You are not in the age range for this survey")
    #Jump back to first question here
    if q == "foo":
        #break the loop

while True:
    gender = input("Are you a male or female (M/F)? ").lower()
    check_gender(gender)

    age = input("Please enter your age: ")
    check_age(age) 

    #And so on with questions

这可能吗？

Answer 1

最好的方法可能是在问题函数内部引发自定义异常，如下所示：

#!/usr/bin/env python
# -*- coding: utf-8 -*-

NUMBER_MEN, NUMBER_WOMEN = 0, 0


class ExitLoop(Exception):

    pass


def check_gender(reply):
    global NUMBER_WOMEN, NUMBER_MEN
    while True:
        if reply == "f":
            NUMBER_WOMEN += 1
            return
        elif reply == "m":
            NUMBER_MEN += 1
            return
        elif reply == "foo":
            raise ExitLoop
        else:
            print("Please answer M or F: ")
            reply = input("Are you a male or female (M/F)? ").lower()


def check_age(reply):
    if reply == "foo":
        raise ExitLoop
    if not 16 <= int(reply) <= 25:
        print("You are not in the age range for this survey")
        return False
    return True


while True:
    try:
        gender = input("Are you a male or female (M/F)? ").lower()
        check_gender(gender)

        age = input("Please enter your age: ")
        inrange = check_age(age)
        if not inrange:
            continue
    except ExitLoop:
        break

我对您的代码进行了一些其他更改，使其更加pythonic。请注意，当用户输入“foo”或回答年龄问题的数字时，上面的代码会失败。

顺便说一句，如果您想向用户提出很多问题，可能需要查看优秀的Click package。

希望这有帮助！

Answer 2

你应该尝试这个代码，有人把其他字母循环打破

def check_gender(q):
    if q == "f":
        number_women = number_women + 1
    elif q == "m":
        number_men = number_men + 1
    # elif q == "foo":
         #break the loop
    else:
        print("Please answer M or F: ")
        q = input("Are you a male or female (M/F)? ").lower()
        check_gender(q)



def check_age(q):
    if not(16 <= int(q) <= 25):
        print("You are not in the age range for this survey")
    #Jump back to first question here
    #if q == "foo":
        #break the loop

while True:
    gender = input("Are you a male or female (M/F)? ").lower()
    if gender != "f" and gender != "m":
        break
    else:
        check_gender(gender)

    age = input("Please enter your age: ")
    try:
        ageValue = int(age)
        check_age(age)
    except ValueError:
        print ("You must enter a number")
        break

从函数中断或继续while循环

2 个答案: