Input from keyboard in python

Question

I write a simple factorial function in python to know the factorial of n . As like we given n and it shows the factorial of n . But the problem is , i use raw_input function to get the value of n. But can't work with that . What can i do to do with raw_input ?

Paste your code, so that people can understand your issue clearly.. — Ravi Kumar, Mar 26 '16 at 05:58
Can you accept my answer if you find it correct?! I also suggested the same what @XYZ Programmer suggested, and I answered before him. — Ayush Mishra, Mar 28 '16 at 02:26

Ayush Mishra · Answer 1 · 2016-03-26T06:10:27.400

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Your factorial function probably takes an integer as input.

However, raw_input returns a string.

So you either need to convert the returned string to an integer. By using int().

Or you can directly use input() which returns an integer in Python2.

edited Mar 26 '16 at 06:10

answered Mar 26 '16 at 05:58

Ayush Mishra

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`input()` returns a string in python 3 so your last line makes no sense (plus using`input()` in python 2 is a really bad idea) – Tadhg McDonald-Jensen Mar 26 '16 at 06:07
My bad, I will edit it. But why's using input() in python2 a really bad idea? – Ayush Mishra Mar 26 '16 at 06:10
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because input wil evaluate whatever the user inputs as a python line. So if they do exit(), for example, the program closes, just like that. – Dleep Mar 26 '16 at 06:19
@AyushMishra if you type in `with open(__file__,"w") as f:f.write("all gone")` from a python2 `input()` it deletes your program file – Tadhg McDonald-Jensen Mar 27 '16 at 17:39
sorry that would raise a SyntaxError, if you wrote `open(__file__,"w").close()` it would erase the file. – Tadhg McDonald-Jensen Mar 27 '16 at 17:50
Woah! Never knew that. Just read that it uses eval. – Ayush Mishra Mar 28 '16 at 02:22

score 0 · Accepted Answer · answered Mar 26 '16 at 06:17

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You need to cast the default string type to int

val = raw_input()    #val accepts a string 

val = int(raw_input())   #val takes integer input

answered Mar 26 '16 at 06:17

XZ6H

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That's exactly what I answered. – Ayush Mishra Mar 26 '16 at 06:24
You could have at least provided an example supporting your answer instead of down voting. – XZ6H Mar 26 '16 at 06:34

Input from keyboard in python

2 Answers2