Python 的 input() 与 raw_input()

Python中用于接收键盘输入的方法有input()与raw_input()。
input()方法被调用时，程序会被暂停直到用户以enter键结束输入。

name = input("What's your name? ")print("Nice to meet you " + name + "!")age = input("Your age? ")print("So, you are are already " + str(age) + " years old, " + name + "!")

run

What's your name? "Frank"Nice to meet you Frank!Your age? 30So, you are are already 30 years old, Frank!

input(）只能读取一个合法的python表达式，一旦字符串输入缺少引号或者其它问题程序将会抛出SyntaxError 异常。
下面比教raw_input()方法

 >>> raw_input_test = raw_input("raw_input: ")raw_input: 123>>> type(raw_input_test)<type 'str'>>>> input_test = input("input: ")input: 123>>> type(input_test)<type 'int'>

raw_input() 将所有输入作为字符串看待，返回字符串类型。而 input() 在对待纯数字输入时具有自己的特性，它返回所输入的数字的类型（int, float甚至是tuple,list等）。

由官方文档 Built-in Functions 可知：

input([prompt])    Equivalent to eval(raw_input(prompt)) 

input() 本质上还是使用 raw_input() 来实现的，只是调用完 raw_input() 之后再调用 eval() 函数，所以它会计算表达式的值并返回它。

例如：

>>> age = raw_input("Your age? ")Your age? 38>>> print(age, type(age))('38', <type 'str'>)>>> >>> age = int(raw_input("Your age? "))Your age? 42>>> print(age, type(age))(42, <type 'int'>)>>> >>> programming_language = raw_input("Your favourite programming languages? ")Your favourite programming languages? ["Python", "Lisp","C++"]>>> print(programming_language, type(programming_language))('["Python", "Lisp","C++"]', <type 'str'>)>>> >>> programming_language = eval(raw_input("Your favourite programming languages? "))Your favourite programming languages?  ["Python", "Lisp","C++"]>>> print(programming_language, type(programming_language))(['Python', 'Lisp', 'C++'], <type 'list'>)