How to use input string as variable call in python?

Question

I am a beginner python learner. I was wondering if it was possible to create a basic massage encrypting system without using any modules. I want my programm to check and use variable name that is in string.

let's say,

a = 'l'
b = '5'
c = 'o'

x = input("Enter your massage: ")

print(x, 'THE_USER INPUT matching the variable name and values')

I know I can do this with while or if, but it would take forever. Also, how do you separate each string letters before you match the variable.

I am using python 3. Thanks :)

its not clear what you are trying to do...

Joran Beasley
– Joran Beasley

2012-09-21 23:39:16 +00:00
Commented Sep 21, 2012 at 23:39 — Joran Beasley
– Joran Beasley, Commented Sep 21, 2012 at 23:39
I was equally confused when I wrote this, sorry.

John Xc
– John Xc

2012-09-22 00:07:59 +00:00
Commented Sep 22, 2012 at 0:07 — John Xc
– John Xc, Commented Sep 22, 2012 at 0:07

sberry · Accepted Answer · 2012-09-21 23:49:34Z

2

I have no idea if this is what you are trying to do, but here goes:

a = 'l'
b = '5'
c = 'o'

x = input("Enter your message: ")
values = [globals().get(var, '') for var in list(x)]

print "".join(values)

EXAMPLE

Enter your message: abc
l5o

A more appropriate way to do this would likely be:

replacements = { 'a': 'l', 'b': '5', 'c': 'o' }

x = input("Enter your message: ")
print "".join([replacements.get(val, "") for val in x])

edited Sep 21, 2012 at 23:49

answered Sep 21, 2012 at 23:44

sberry

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4 Comments

Joran Beasley Over a year ago

on a side note while this is what the OP asked for this is probably not really what they should be doing...

sberry Over a year ago

Completely and totally agree.

Joran Beasley Over a year ago

your more appropriate way is a significant improvement. .. but really he should be using string.translate for this ...

John Xc Over a year ago

Thanks This is exactly what I was looking for. I will now have to check out references to understand the new syntax. Thanks :)

Joran Beasley · Accepted Answer · 2012-09-21 23:50:11Z

1

use string.translate this is a much more correct way to do what it sounds like you want

from string import maketrans

in_tab  = "abcdefghijklmnopqrstuvwxyz "
out_tab = "5QR&*(=-;Wwz%$^#@!yY~:123xq"

t = maketrans(in_tab,out_tab)
print ("Hello World".translate(t))

answered Sep 21, 2012 at 23:50

Joran Beasley

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1 Comment

John Xc Over a year ago

This is pretty much what I wanted to do, but i don't want any help from any modules. Thanks, I didn't know I could do that. I will use this methods in future :)

zpea · Accepted Answer · 2012-09-22 00:15:40Z

1

In case you meant substituting every occurrence of a given character by another one, have a look at the str.translate function.

You could extend your example code as follows:

import string

in = input("Enter your message: ")
mapping = string.maketrans('abc', '15o')
out = in.translate(mapping)
print(out)

Every a is substituted by a 1, every b by 5, every c by o.

edited Sep 22, 2012 at 0:15

answered Sep 22, 2012 at 0:09

zpea

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3 Comments

John Xc Over a year ago

Thanks, but I was looking for a method that works without importing any module. I think this requires module. But it seems easier and I will use it later on :)

zpea Over a year ago

You are right, added the missing import. But using modules is nothing to avoid! Do not try to reinvent the wheel :) Especially not for such common and tedious/error-prone tasks as string manipulation.

zpea Over a year ago

BTW: The import is just necessary for the maketrans helper function, it just builds a 256 character-long string for you that you could specify yourself. Not that anybody would want to do that.

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