第七章课后练习题

7-1 汽车租赁 : 编写一个程序,询问用户要租赁什么样的汽车,并打印一条消息,如“Let me see if I can find you a Subaru”。
代码：name = input ("Hello, what kind of car would you like to have?")
print("Let me see if I can find you a " + name + ".")结果：Hello, what kind of car would you like to have?Lamborghini
Let me see if I can find you a Lamborghini.
7-2 餐馆订位 : 编写一个程序,询问用户有多少人用餐。如果超过8人,就打印一条消息,指出没有空桌;否则指出有空桌。
代码：number = input ("Hello, how many people do you have?")
number = int(number)
if number > 8 :
print("Sorry, there is no table for you.")
else :
print("Ok, there are tables for you to choose.")结果：Hello, how many people do you have?9
Sorry, there is no table for you.
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。 
代码：

number = input ("Please input a number?")
number = int(number)
num = number % 10
if num==0 :
print("The number is a multiplier of 10")
else :
print("The number isn't a multiplier of 10")

结果：
(10的倍数)Please input a number?100
The number is a multiplier of 10（非10的倍数）

Please input a number?9
The number isn't a multiplier of 10

7-4 比萨配料 :编写一个循环,提示用户输入一系列的比萨配料,并在用户输入'quit' 时结束循环。每当用户输入一种配料后,都打印一条消息,说我们会在比萨中添加这种配料。
代码：message = "\nPlease input one ingredient:"
message += "\n(Enter 'quit' when you are finished.)"

while True:
t = input(message)
if t == "quit":
break
else :
print("We will add it to the pizza.")结果：Please input one ingredient:
(Enter 'quit' when you are finished.)eggs
We will add it to the pizza.

Please input one ingredient:
(Enter 'quit' when you are finished.)pork
We will add it to the pizza.

Please input one ingredient:
(Enter 'quit' when you are finished.)cheeze
We will add it to the pizza.

Please input one ingredient:
(Enter 'quit' when you are finished.)quit
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。
代码：message = "\nPlease input your age :"
message += "\n(Enter 'quit' when you are finished.)"

while True:
t = input(message)
if t== "quit":
break
else:
t = int (t)
if t<=3:
print("The tickets are free for you.")
elif 3<t and t<=12 :
print("You should pay 10 dollars.")
elif t>12:
print("You should pay 15 dollars.") 结果：Please input your age :
(Enter 'quit' when you are finished.)3
The tickets are free for you.

Please input your age :
(Enter 'quit' when you are finished.)5
You should pay 10 dollars.

Please input your age :
(Enter 'quit' when you are finished.)13
You should pay 15 dollars.

Please input your age :
(Enter 'quit' when you are finished.)quit
7-6 三个出口 :以另一种方式完成练习7-4或练习7-5,在程序中采取如下所有做法。    
    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。
代码：message = "\nPlease input your age :"
message += "\n(Enter 'quit' when you are finished.)"

active = True

while active:
t = input(message)
if t== "quit":
active = False
break
else:
t = int (t)
if t<=3:
print("The tickets are free for you.")
elif 3<t and t<=12 :
print("You should pay 10 dollars.")
elif t>12:
print("You should pay 15 dollars.") 结果：Please input your age :
(Enter 'quit' when you are finished.)3
The tickets are free for you.

Please input your age :
(Enter 'quit' when you are finished.)5
You should pay 10 dollars.

Please input your age :
(Enter 'quit' when you are finished.)13
You should pay 15 dollars.

Please input your age :
(Enter 'quit' when you are finished.)quit
7-7 无限循环 :编写一个没完没了的循环,并运行它(要结束该循环,可按Ctrl +C,也可关闭显示输出的窗口)。 
代码：active = True

while active:
print("1")结果： 1
1
1
1
1
1
1
1
1
...

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。
代码：sandwich_orders = ['chicken', 'pork', 'tuna']
finished_sandwiches = []
# 验证每个用户,直到没有未验证用户为止
# 将每个经过验证的列表都移到已验证用户列表中 ❷ while unconfirmed_users:
while sandwich_orders:
current = sandwich_orders.pop()
print("I made your " + current.title() + " sandwich. ")
finished_sandwiches.append(current)

for finished_sandwich in finished_sandwiches:
print(finished_sandwich)结果：I made your Tuna sandwich.
I made your Pork sandwich.
I made your Chicken sandwich.
tuna
pork
chicken
7-9 五香烟熏牛肉(pastrami)卖完了 :使用为完成练习7-8而创建的列表sandwich_orders ,并确保'pastrami' 在其中至少出现了三次。在程序开头附近添加这样的代码:打印一条消息,指出熟食店的五香烟熏牛肉卖完了;再使用一个while 循环将列表sandwich_orders 中的'pastrami' 都删除。确认最终的列表finished_sandwiches 中不包含'pastrami' 。
代码：sandwich_orders = ['chicken', 'pork',"pastrami", "pastrami" , 'tuna', "pastrami"]
print(sandwich_orders)

while "pastrami" in sandwich_orders:
sandwich_orders.remove("pastrami")

print(sandwich_orders)结果：['chicken', 'pork', 'pastrami', 'pastrami', 'tuna', 'pastrami']
['chicken', 'pork', 'tuna']