Question

电影票：电影院根据个人的年龄收取不同的票价。如果一个人未满3岁，则该机票是免费的;如果他们在3到12之间，门票是10美元;如果他们超过12岁，门票是15美元。写一个循环，在其中询问用户的年龄，然后告诉他们电影票的费用。

我希望这个程序具有戒烟价值。我可以使用0作为我的戒烟值，但我想使用＆＃39;退出＆＃39;。

prompt = "What is your age? "
prompt += "\nEnter 'quit' to close program."

age = 0

while True:


     age = raw_input(prompt)
        if age == 'quit':
            break
        else:
            age = int(age)
            if age < 3:
                print("The movie ticket is FREE for you.")
            elif 3 <= age < 12:
                print("The movie ticket is $10 for you.")
            elif age >= 12:
                print("The movie ticker is $15 for you.")

Answer 1

我想指出你不需要else条款。您可以在前一个缩进级别包含其余条件，因为break退出循环而不是继续循环体的其余部分。

而不是

    if age == 'quit':
        break
    else:
        age = int(age)

简单地：

    if age == 'quit':
        break

    age = int(age)

如果不清楚这里是整个程序的变化：

prompt = "What is your age? "
prompt += "\nEnter 'quit' to close program."

while True:

    age = raw_input(prompt)
    if age == 'quit':
        break

    age = int(age)
    if age < 3:
        print("The movie ticket is FREE for you.")
    elif 3 <= age < 12:
        print("The movie ticket is $10 for you.")
    elif age >= 12:
        print("The movie ticker is $15 for you.")

我还删除了无用的作业：age = 0，因为该值会被age = raw_input(prompt)替换，然后才能被读取。

Answer 2

是的，如果你愿意，你可以嵌套if语句，但我总是先尝试找到更好的方法。在这种情况下，我们可以使用while语句的条件部分。

age = 0
while age != "quit":
    age = raw_input(prompt)
    age = int(age)
    if age < 3:
        print("The movie ticket is FREE for you.")
    elif 3 <= age < 12:
        print("The movie ticket is $10 for you.")
    elif age >= 12:
        print("The movie ticker is $15 for you.")

现在只要age不等于"quit"，代码就会循环播放。

Answer 3

您可以使用try:通过输入othert值而不是整数来避免脚本崩溃。

prompt = "What is your age? [quit to Exit the program] : "
while True:
     age = raw_input(prompt)
     if age == 'quit':
        break
     try:
        age = int(age)
        if age < 3:
            print("The movie ticket is FREE for you.")
        elif 3 <= age < 12:
            print("The movie ticket is $10 for you.")
        elif age >= 12:
            print("The movie ticker is $15 for you.")
     except:
        print 'Invalid Age entered !!!'
        pass

在Python中，是否可以阻塞if-elif-else块？

3 个答案: