【Python基础知识】（六）用户输入与while循环
2021-04-19 21:28
标签：创建 items tle 文本 col 停止 参考 response 运算 使用input()函数可获取用户输入的文本，并以字符串的形式存入变量中。 当输入Carl时的输出： Please enter your name: Carl 有时候，输入提示可能超过一行，此时可将提示存储在一个变量中，再将该变量传递给函数input()。 下例就是使用+=运算符创建多行字符串的一种方式（可理解为字符串的拼接）。 由于Python将用户输入解读为字符串，所以当要让Python将输入视为数值时，需要调用int()函数。 输出为： 在要求很多条件都满足才能继续运行的程序中，可定义一个变量，用于判断整个程序是否处于活动状态，这个变量被称为标志。当标志的值为True时，程序可继续进行；当标志的值为False时，程序停止运行。 多次输入，得到输出为： 在循环中使用break语句，可直接退出循环。 在循环中使用continue语句，可让程序跳过在循环体中位于continue语句后面的所有语句，直接回到循环开始并开始下一轮的循环。 输出为： （运行时删除中文注释，其他程序同） 输出为： 输入一些信息，得到输出为： 参考书籍：《Python编程：从入门到实践》 2020-07-12 【Python基础知识】（六）用户输入与while循环 标签：创建 items tle 文本 col 停止 参考 response 运算 原文地址：https://www.cnblogs.com/carl39/p/13287773.html用户输入
name = input( "Please enter your name: " )
print( "Hello, " + name + "!" )
Hello, Carl!prompt = "Please tell us who you are."
prompt += "\nWhat‘s your first name? "
name = input( prompt )
print( "\nHello, " + name + "!" )
age = input( "How old are you?" ) ‘‘‘输入19‘‘‘
age = int( age )
age >= 18 ‘‘‘True‘‘‘
while循环
1、简单的while循环
current_number = 1
while current_number :
print( current_number )
current_number += 1
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prompt = "Tell me something, and I will repeat it back to you: "
prompt += "\nEnter ‘quit‘ to end the program. "
active = True
while active:
message = input( prompt )
if message == ‘quit‘:
active = False
else:
print( message )
Tell me something, and I will repeat it back to you:
Enter ‘quit‘ to end the program. City
City
Tell me something, and I will repeat it back to you:
Enter ‘quit‘ to end the program. Both
Both
Tell me something, and I will repeat it back to you:
Enter ‘quit‘ to end the program. quit
2、break语句
prompt = "Tell me something, and I will repeat it back to you: "
prompt += "\nEnter ‘quit‘ to end the program. "
while True:
message = input( prompt )
if message == ‘quit‘:
break
else:
print( message )
3、continue语句
current_number = 0
while current_number :
current_number += 1
if current_number %2 == 0:
continue
print( current_number )
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使用while循环处理列表和字典
1、在列表之间移动元素
‘‘‘验证用户‘‘‘
unconfirmed_users = [ ‘alice‘ , ‘brian‘ , ‘candance‘ ]
confirmed_users = [ ]
‘‘‘逐一验证用户‘‘‘
while unconfirmed_users:
current_user = unconfirmed_users.pop()
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_users.title() )
2、删除列表中的特定值
pets = [ ‘dog‘ , ‘cat‘ , ‘dog‘ , ‘goldfish‘ , ‘cat‘ , ‘rabbit‘ , ‘cat‘ ]
print( pets )
while ‘cat‘ in pets:
pets.remove( ‘cat‘ )
print( pets )
[‘dog‘, ‘cat‘, ‘dog‘, ‘goldfish‘, ‘cat‘, ‘rabbit‘, ‘cat‘]
[‘dog‘, ‘dog‘, ‘goldfish‘, ‘rabbit‘]
3、将输入存储进字典
responses = { }
‘‘‘设置标志‘‘‘
polling_active = True
while polling_active:
‘‘‘获取需要加入字典的键-值对信息‘‘‘
name = input( "\nWhat‘s your name? " )
response = input( "which mountain would you like to climb someday?" )
‘‘‘将键-值对录入字典‘‘‘
responses[ name ] = response
‘‘‘是否要执行下一轮循环‘‘‘
repeat = input( "Asking another person?(yes/no)" )
if repeat == ‘no‘:
polling_active = False
‘‘‘调查结束，显示结果‘‘‘
print( "\n--- Poll Results ---" )
for name, response in responses.items():
print( name + " would like to climb " + response + "." )
What‘s your name? Eric
which mountain would you like to climb someday?Denali
Asking another person?(yes/no)yes
What‘s your name? Lynn
which mountain would you like to climb someday?Devil‘s Thumb
Asking another person?(yes/no)no
--- Poll Results ---
Eric would like to climb Denali.
Lynn would like to climb Devil‘s Thumb.
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