7-1
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”。
car = input('Which car do you like?')
print('Let me see if I can find you a ' + car + '.')
7-2
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。
number = int(input('How many people are going to have lunch?'))
if number > 8:
print('There is no table.')
else:
print('There are empty tables.')
7-3
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 = int(input('Please input a number:'))
if number % 10 == 0:
print('It is divisible by 10.')
else:
print('It is not divisible by 10.')
7-4
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。
while True:
str = input('Please input a ingredient:')
if str == 'quit':
break
else:
print("I'll add " + str + " on pizza.")
7-5
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。
while True:
age = int(input('Please input your age:'))
if age < 3:
print('Free')
elif age <= 12:
print('10 dollar')
else:
print('15 dollor')
7-6
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。
str = input('Please input a ingredient:')
while str != 'quit':
print("I'll add " + str + " on pizza.")
str = input('Please input a ingredient:')
active = True
while active:
str = input('Please input a ingredient:')
if str == 'quit':
active = False
else:
print("I'll add " + str + " on pizza.")
while True:
str = input('Please input a ingredient:')
if str == 'quit':
break
else:
print("I'll add " + str + " on pizza.")
7-7
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)。
while True:
print('running...')
7-8
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_orders = ['a', 'b', 'c']
finished_sandwiches = []
while sandwich_orders:
sandwich = sandwich_orders.pop()
print('I made your sandwich ' + sandwich)
finished_sandwiches.append(sandwich)
for sandwich in finished_sandwiches:
print(sandwich)
7-9
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’ 。
sandwich_orders = ['a', 'pastrami', 'b', 'pastrami', 'pastrami']
print('Pastrami has been sold out.')
while 'pastrami' in sandwich_orders:
sandwich_orders.remove('pastrami')
for sandwich in sandwich_orders:
print(sandwich)
7-10
编写一个程序,调查用户梦想的度假胜地。使用类似于“If you could visit one place in the world, where would you go?”的提示,并编写一个打印调查
结果的代码块。
responses = {}
polling_active = True
while polling_active:
name = input("\nWhat is your name? ")
response = input("If you could visit one place in the world, where would you go?")
responses[name] = response
repeat = input("Would you like to let another person respond? (yes/ no) ")
if repeat == 'no':
polling_active = False
print("\n--- Poll Results ---")
for name, response in responses.items():
print(name + " would like to climb " + response + ".")