7.3使用 while循环来处理列表和字典

1.在列表之间移动元素

 

#首先创建一个待验证用户列表

#再创建一个用于存储已验证用户的空列表
unconfirmed_users=['alice','brian','tom']
confirmed_users=[]


#验证每个用户,将每个经过验证的元素都移到已验证用户列表中

#pop()函数每次从列表unconfirmed_users末尾删除一个的用户
#title() 方法返回"标题化"的字符串,单词以大写开始，其余字母均为小写
#append() 方法用于在列表末尾添加新的对象


while unconfirmed_users:
    curent_user=unconfirmed_users.pop()
    print("Verifying user:"+curent_user.title())
    confirmed_users.append(curent_user)




#显示所有已验证的用户
print("\nThe following users have been confirmed:")
for confirmed_user in confirmed_users:
    print(confirmed_user.title())

 运行结果：

>>> 
================ RESTART: D:\python学习\7.3\confirmed_users.py ================
Verifying user:Tom
Verifying user:Brian
Verifying user:Alice

The following users have been confirmed:
Tom
Brian
Alice
>>> 

 2.删除包含特定值的所有所表元素

 

#删除列表中所有包含特定值的元素
pets=['dog','cat','dog','goldfish','cat','rabbit','cat']

print(pets)

while 'cat' in pets:
    pets.remove('cat')

print()
print(pets)

 

 运行结果：

====================== RESTART: D:/python学习/7.3/pets.py ======================
['dog', 'cat', 'dog', 'goldfish', 'cat', 'rabbit', 'cat']

['dog', 'dog', 'goldfish', 'rabbit']
>>> 

 3.使用用户输入来填充字典

 

#使用用户输入来填充字典
#每次循环提示输入被调查者的名字和回答，收集的数据存放在一个字典中

responses={}
polling_active=True

while polling_active:
    
    name=input("\nWhat's your name?")
    response=input("Which mountain would you like to climb someday?")
    responses[name]=response#将答案填充到字典中
    repeat=input("Y/N?")#设置一个标志，决定是否继续
    if repeat=='N':
        polling_active=False

print("\n===========Poll Results========== ")    #调查结束，显示结果
for name,response in responses.items():
    print(name+" would like to climb "+response+'.')     

'''
注意：
1.填充字典的方法
2.字典输出的方法

'''

 运行结果：

>>> 
====================== RESTART: D:/python学习/7.3/填充字典.py ======================

What's your name?张三
Which mountain would you like to climb someday?泰山
Y/N?Y

What's your name?Tom
Which mountain would you like to climb someday?Alps
Y/N?N

===========Poll Results========== 
Tom would like to climb Alps.
张三 would like to climb 泰山.
>>>