input和while循环——Python编程从入门到实践
2020-12-13 03:23
标签：信息 针对 name lse 模运算符 mes ges 活动 pre input()函数：让程序运行暂停，等待用户输入。 运行结果： 提示信息超过一行时： 通过input()函数输入的信息以字符串的形式存储，若需要将输入作为数值使用怎么办呢？ 可以使用int()函数将其转换为数值表示： 求模运算符（%）：求得两数相除返回的余数。 可用于判断一个数是奇数还是偶数： 运算符两端的元素类型要一致，故print语句中又需要将数值型通过str()函数转换为字符型。 for循环是针对集合中的每个元素的一个代码块，而while循环是不断的运行，直到指定条件不满足。 运行结果： 运行结果： 输入为 quit 时循环结束。 若不想将 quit 也作为一条消息打印出来，则： 在要求很多条件都满足的情况下才继续运行的程序中，可定义一个变量，用于判断整个程序是否处于活动状态，这个变量称为标志。 敲代码的时候把 active = False 敲成了 active = ‘False‘，然后输入quit还一直执行循环，哈哈哈 Note: Python循环（while循环、for循环）中都可使用break语句来推出循环。 循环中使用continue，会返回大循环开头，并根据条件测试结果决定是否继续执行循环： 运行结果： 上述的代码块中，若漏写了代码行 x += 1，这个程序将没完没了地运行。可按Ctrl + C，也可关闭显示程序输出的终端窗口，或关闭编辑器，结束无限循环。 input和while循环——Python编程从入门到实践 标签：信息 针对 name lse 模运算符 mes ges 活动 pre 原文地址：https://www.cnblogs.com/shirley-yang/p/11073782.htmlinput( )
message = input(‘Tell me something, and I will repeat it back to you: ‘)
print(message)
Tell me something, and I will repeat it back to you: Hello Python!
Hello Python! 1. 编写清晰的程序
name = input("Please enter your name: ")
print("Hello, " + name + "!")
Please enter your name: hery
Hello, hery!
prompt = "If you tell us who you are, we can personalize the messages you see."
prompt += ‘\nWhat is your name? ‘
name = input(prompt)
print("\nHello, " + name + "!")
2. 获取数值的输入
age = input("How old are you? ")
print(type(age))
How old are you? 12
class ‘str‘>
height = input("How tall are you, in inches? ")
height = int(height)
if height >= 36:
print("\nYou‘re tall enough to ride!")
else:
print("\nYou‘ll be able to ride when you‘re a little older.")
3. 求模运算符
number = input("Enter a number, and I‘ll tell you if it is even or odd: ")
number = int(number)
if number % 2 == 0:
print(‘\nThe number ‘ + str(number) + ‘ is even.‘)
else:
print(‘\nThe number ‘ + str(number) + ‘ is odd.‘)
while循环
1. 使用while循环
current_number = 1
while current_number :
print(current_number)
current_number += 1
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2. 让用户选择何时退出
prompt = "\nTell me something , and I will repeat it back to you:"
prompt += "\nEnter ‘quit‘ to end the program. "
message = ‘‘
while message != ‘quit‘:
message = input(prompt)
print(message)
Tell me something , and I will repeat it back to you:
Enter ‘quit‘ to end the program. Hello Python
Hello Python
Tell me something , and I will repeat it back to you:
Enter ‘quit‘ to end the program. Hello 0629
Hello 0629
Tell me something , and I will repeat it back to you:
Enter ‘quit‘ to end the program. quit
quit
prompt = "\nTell me something , and I will repeat it back to you:"
prompt += "\nEnter ‘quit‘ to end the program. "
message = ‘‘
while message != ‘quit‘:
message = input(prompt)
if message != ‘quit‘:
print(message)
3. 使用标志
prompt = "\nTell 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)
4. 使用break退出循环
prompt = "\nPlease enter the name of a city you have visited:"
prompt += "\n(Enter ‘quit‘ when you are finished.) "
while True:
city = input(prompt)
if city == ‘quit‘:
break
else:
print("I‘d love to go to " + city.title() + "!")
5. 在循环中使用continue
current_number = 0
while current_number :
current_number += 1
if current_number % 2 == 0:
continue
else:
print(current_number)
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6. 避免无限循环
x = 1
while x :
print(x)
x += 1
文章标题：input和while循环——Python编程从入门到实践
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