7.1、函数input()
用int()将输入转换成整型
求模运算符：%，用于两数相除返回余数。eg. 100%10=0
练习：
# coding=GBK
#7-1
car=input('What car do you wanna rent?')
print('Let me see if I can find you a Subaru' )
#7-2
people=input('How many peole eat?')
people=int(people)
if people > 8:
print('There is no empty table.')
else:
print('Free table')
#7-3
number=input('Enter a number,and I will tell if it is a multiple of 10 ')
number=int(number)
if number%10 == 0:
print('It is a multiple of 10')
else:
print("It isn't")
7.2 while 循环
while循环不断运行。当指定条件不满足时，退出循环。
使用标志用于判断程序是否处于活动状态。True运行，False结束。
用break退出循环。
用continue结束此次循环，进入下次循环。
务必对每个While循环进行测试，以免进入无限循环。当进入无限循环时，按Ctrl+C退出或关闭窗口。
相关练习
#7-4
print('Please add your ingredient: ')
a=''
while a != 'quit':
a=input()
if a != 'quit':
print('We will add '+a)
else:
print('Please wait a minute')
#7-5 and 7-6
prompt='Please enter your age: '
prompt+='\ninput quit to exit.'
active=True
while active:
age=input(prompt)
if age=='quit':
break
else:
if int(age) < 3:
print('Free')
elif int(age) <= 12:
print('Please pay $10.')
else:
print('Please pay $15.')
7.3 用while处理列表和字典
在列表间移动元素：
练习：
#7-8、7-9
解一：
sandwich_orders=['A','pastrami','C','pastrami','E','pastrami']
print('Pastrami is sold out')
finished_sandwich=[]
b=0
while b < len(sandwich_orders):
a=sandwich_orders[b]
if a.lower() == 'pastrami':
b=b+1
continue
else:
finished_sandwich.append(a)
print('I made your '+a)
b=b+1
print(finished_sandwich)
删除列表内的特定值：
#7-9
sandwich_orders=['A','pastrami','C','pastrami','E','pastrami']
print('Pastrami is sold out')
finished_sandwich=[]
while 'pastrami' in sandwich_orders:
sandwich_orders.remove('pastrami')
finished_sandwich=sandwich_orders
print(finished_sandwich)
使用用户输入填充字典：
7-10
#coding=GBK
places={}
active=True
while active:
name=input('姓名：')
place=input('梦想的度假胜地：')
places[name]=place
repeat=input('还有人要回答吗？(yes/no)')
if repeat.lower() =='no':
active=False
print('调查结果')
for name,place in places.items():
print(name+'想去'+place+'.')