[第四周]第七章课后习题

7-3 10的整数倍 ：让用户输入一个数字，并指出这个数字是否是10的整数倍。

number=input("Please enter a number:")
if int(number)%10:
    print(number+" is not an integer multiple of 10!")
else:
    print(number + " is an integer multiple of 10!")

输出：

Please enter a number:5
5 is not an integer multiple of 10!

Please enter a number:20
20 is an integer multiple of 10!

7-5 电影票 ：有家电影院根据观众的年龄收取不同的票价：不到3岁的观众免费；3~12岁的观众为10美元；超过12岁的观众为15美元。请编写一个循环，在其中询问用户的年龄，并指出其票价。
·在while 循环中使用条件测试来结束循环。
·使用变量active 来控制循环结束的时机。
·使用break 语句在用户输入’quit’ 时退出循环。

方法一：

number=0
#人数少于3人
while number<3:
    age=input("How old are you?\n")
    out="The price of your ticket is: "
    age=int(age)
    if age<3:
        out += "Free"
    elif age<12:
        out += "10."
    else:
        out += "15."
    print(out)
    number = number+1
    print("\n")

输出：

How old are you?
2
The price of your ticket is: Free


How old are you?
8
The price of your ticket is: 10.


How old are you?
13
The price of your ticket is: 15.

方法二：

active=True
while active:

    age=input("How old are you?\n")
    out="The price of your ticket is: "
    if age=="quit":
        active=False
    else:
        age=int(age)
        if age<3:
            out += "Free"
        elif age<12:
            out += "10."
        else:
            out += "15."
        print(out)
        print("\n")

输出：

How old are you?
2
The price of your ticket is: Free


How old are you?
10
The price of your ticket is: 10.


How old are you?
19
The price of your ticket is: 15.


How old are you?
quit

方法三：

while True:
    age=input("How old are you?\n")
    out="The price of your ticket is: "
    if age=="quit":
        break
    else:
        age=int(age)
        if age<3:
            out += "Free"
        elif age<12:
            out += "10."
        else:
            out += "15."
        print(out)
        print("\n")

输出：

How old are you?
1
The price of your ticket is: Free


How old are you?
10
The price of your ticket is: 10.


How old are you?
18
The price of your ticket is: 15.


How old are you?
quit

7-8 熟食店 ：创建一个名为sandwich_orders 的列表，在其中包含各种三明治的名字；再创建一个名为finished_sandwiches 的空列表。遍历列表sandwich_orders ，对于其中的每种三明治，都打印一条消息，如I made your tuna sandwich ，并将其移到列表finished_sandwiches 。所有三明治都制作好后，打印一条消息，将这些三明治列出来。

sandwich_order=["Apple","chicken","tuna"]
finished_sandwiches=[]
while sandwich_order:
    sandwich=sandwich_order[0]
    print("I made your "+sandwich+" sandwich")
    sandwich_order.remove(sandwich)
    finished_sandwiches.append(sandwich)
print(finished_sandwiches)

输出：

I made your Apple sandwich
I made your chicken sandwich
I made your tuna sandwich
['Apple', 'chicken', 'tuna']