How to write a recursive function without calling for raw input more than once?

Question

I want to write this recursively to encode other letters in the string with ord and chr, but when I write it recursively it calls for raw_input from user again. How do i fix this?

def rawEncode(input):
    input= raw_input("GIVE ME SUPER SECRET MESSAGE TO ENCODE")
    unencoded="%s" %input [:]
    if "%s" %input =='':
        return ''
    else:
        answer=ord("%s" %input [0])
        return answer

Put the input outside of your method? – idjaw Feb 27 '16 at 17:16 — idjaw, Feb 27 '16 at 17:16
@idjaw i did that it works – Robert903 Feb 27 '16 at 18:06 — Robert903, Feb 27 '16 at 18:06

Andriy Ivaneyko · Answer 1 · 2016-02-27T17:29:01.333

0

It's better to get input and encode string in separate places. However you can get desired recursion by adding additional flag which disable input forcing and modifying return values to be a list for further concatting of ords:

def rawEncode(input='', force_input=True):
    if force_input:
        input= raw_input("GIVE ME SUPER SECRET MESSAGE TO ENCODE")
    if "%s" % input == '':
        return ['']
    else:
        answer = ord("%s" %input [0])
        return [answer] + rawEncode(input=input[1:], force_input=False)

print rawEncode()

edited Feb 27 '16 at 17:29

answered Feb 27 '16 at 17:23

Andriy Ivaneyko

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From a pure design viewpoint I think it'd make more sense to have the function just take the input (as a required parameter) and have the caller put it in. – Matti Virkkunen Feb 27 '16 at 17:27

score 0 · Answer 2 · answered Feb 27 '16 at 17:27

0

You can simply put the statement
input= raw_input("GIVE ME SUPER SECRET MESSAGE TO ENCODE")
before the function call.

answered Feb 27 '16 at 17:27

XZ6H

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score 0 · Answer 3 · edited Feb 27 '16 at 18:27

0

it is very simple

TempVar = 0

def rawEncode(input):

    if TempVar == 0:
        input = raw_input("GIVE ME SUPER SECRET MESSAGE TO ENCODE")
        TempVar = TempVar + 1

    unencoded = "%s" % input[:]
    if "%s" % input == '':
        return ''
    else:
        answer = ord("%s" % input[0])
        return answer

edited Feb 27 '16 at 18:27

ekhumoro

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answered Feb 27 '16 at 17:57

hb X

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How to write a recursive function without calling for raw input more than once?

3 Answers3