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 '