python第7章用户输入和while循环

用户输入和while循环"/>

python第7章用户输入和while循环

案例：在列表之间移动元素

confirmed_users.py
#首先，创建一个待验证用户列表和一个用于存储已验证用户的列表
unconfirmed_users=[‘alice’,‘brain’,‘candace’]
confirmed_users=[]
#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
while unconfirmed_users:
current_user=unconfirmed_users.pop()
#pop()方法每次从列表末尾删除并存储到current_user中
print("Verifying user: “+current_user.title())
confirmed_users.append(current_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())

#测试如下

Verifying user: Candace

Verifying user: Brain

Verifying user: Alice

The following users have been confirmed:

Candace

Brain

Alice

案例：删除包含特定值的所有列表元素 pets.py

pets=[‘dog’,‘cat’,‘dog’,‘goldfish’,‘cat’,‘rabbit’,‘cat’]
print(pets)
while ‘cat’ in pets:
pets.remove(‘cat’)
print(pets)

#测试如下

[‘dog’, ‘cat’, ‘dog’, ‘goldfish’, ‘cat’, ‘rabbit’, ‘cat’]

[‘dog’, ‘dog’, ‘goldfish’, ‘rabbit’]

案例：使用用户输入来填充字典 mountain_poll.py

responses={}

设置一个标志，指出调查是否继续

polling_active=True

while polling_active:
name=input("\nWhat is your name? ")
response=input("Which mountain would you like to climb someday? ")

#将答案存储在字典中
responses[name]=response
#看看是否还有人要参与调查
repeat=input("Would you like to let another person respond? (yes/no) ")
if repeat=='no':polling_active=False

#显示结果
print("\n—Poll Results—")
for name,response in responses.items():
print(name+ " would like to climb “+response+”.")

#测试如下

What is your name? Eric

Which mountain would you like to climb someday? Denali

Would you like to let another person respond? (yes/no) yes

What is your name? Lymn

Which mountain would you like to climb someday? ABC

Would you like to let another person respond? (yes/no) no

—Poll Results—

Ericwould like to climb Denali.

Lymnwould like to climb ABC.