Python 学习笔记（七）Python字符串（四）

输入输出

输入函数 raw_input (Python3:input)

 >>> raw_input("请输入一个字母") #获取输入内容的一个函数
 请输入一个字母A
 'A'
 >>>
 >>> name = raw_input("Please input your name:") #输入得内容赋值给一个变量
 Please input your name:tom
 >>> name
 'tom'
 >>> x =raw_input("how old are you?")
 how old are you?x =raw_input("how old are you?")
 >>> x =raw_input("how old are you?")
 how old are you?22
 >>> x
 ''
 >>> type(x)  #通过raw_input 得到的结果是一个字符串类型
 <type 'str'>
 >>> help(raw_input) #查看raw_input详细内容
 Help on built-in function raw_input in module __builtin__:

 raw_input(...)
     raw_input([prompt]) -> string   返回值字符串

     Read a string from standard input.  The trailing newline is stripped.
     If the user hits EOF (Unix: Ctl-D, Windows: Ctl-Z+Return), raise EOFError.
     On Unix, GNU readline is used if enabled.  The prompt string, if given,
     is printed without a trailing newline before reading.

print()格式化

print 在python2中是一个语句 ，在python3中print() 是一个函数

格式化   指定一种格式，按照某种格式打印出来,

　　　　制定一种模板,在模板中某个地方留出一些空位，在空位上填上某些内容，那么这些空位就需要一些符号来表示，通常称之为占位符

%s  字符串占位符

%d  整数占位符

%f  浮点数占位符

 >>> "I LIKE %s"
 'I LIKE %s'
 >>> "I Like %s"%"Python"  #用%之后的Python 来填充%s这个占位符
 'I Like Python'
 >>> a = "I Like %s" >>> a %"java"
 'I Like java'
 >>> print "%s was born in %d "%("tom",2018)  #括号中为字符串和数字
 tom was born in 2018
 >>>

用花括号{}索引值 占位符 Python 推荐使用  {}

　　 str.format() 格式化

 >>> s = "I like {0}"
 >>> s.format("Python")
 'I like Python'
 >>> s2 ="%s was born in %d "%("tom",2018)
 >>> s2.format("tom",2018)
 'tom was born in 2018 '