python里的input,,python2和py
python里的input,,python2和py
python2和python3的input是不同的
python3的input
对于python3,只有input,官方文档里是这样描述的
def input(*args, **kwargs): # real signature unknown """ Read a string from standard input. The trailing newline is stripped. The prompt string, if given, is printed to standard output without a trailing newline before reading input. If the user hits EOF (*nix: Ctrl-D, Windows: Ctrl-Z+Return), raise EOFError. On *nix systems, readline is used if available. """ pass
意思就是:读取一个字符串并输入,舍弃结尾的换行符
a = input()print(a, type(a))b = input()print(b, type(b))
控制台输出结果
hellohello <class 'str'>123123 <class 'str'>
python2的input
python2有input和raw_input两种输入
input
a = input()print(a, type(a))b = input()print(b, type(b))
控制台输出结果
123(123, <type 'int'>)helloTraceback (most recent call last): File "D:/input_test/test.py", line 11, in <module> b = input() File "<string>", line 1, in <module>NameError: name 'hello' is not defined
报错了!这是因为input是获取原始的输入内容,也就是说,输入什么,就会得到什么
官方文档是这样描述的
def input(prompt=None): # real signature unknown; restored from __doc__ """ input([prompt]) -> value Equivalent to eval(raw_input(prompt)). """ pass
如果要输入字符串,需要手动加引号
a = raw_input()print(a, type(a))b = raw_input()print(b, type(b))# 控制台输出结果123(123, <type 'int'>)'hello'('hello', <type 'str'>)
raw_input
raw_input与python3里面的input一样,输入的内容都会转化成字符串
a = raw_input()print(a, type(a))b = raw_input()print(b, type(b))
控制台输出结果
123('123', <type 'str'>)hello('hello', <type 'str'>)
小结
python3只有input,输入的数据都会转化成字符串python2有input和raw_input,input读取原始的数据类型,输入什么就得到什么;raw_input获取到的都是字符串类型补充:关于input的底层实现,参考博客 python中print和input的底层实现
python里的input
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