How would I replace a single character in a string?

Question

I'm coding a little python program for ROT13.

If you don't know what it means, it means it will replace the letter of the alphabet to 13th letter in front of it therefore 'a' would become 'n'.

A user will ask for an input and I shall replace each character in the sentence to the 13th letter in front.

This means I need to replace each character, now who would I do that?

I tried importing the re function but It didn't work. This is what I got so far.

import re

Alpha = input("Input the word you would like translated")


Alpha = re.sub('[abcdefghijklmnopqrstuvwxyz]', 'nopqrstuvwxyzabcdefghijklm', 
Alpha)
print(Alpha)

Help would be very much appreciated.

Answer 1

re.sub('[abcdefghijklmnopqrstuvwxyz]', 'nopqrstuvwxyzabcdefghijklm', Alpha)

would just replace every character of the alphabet with nopqrstuvwxyzabcdefghijklm.

Take a look at str.translate.

Answer 2

You can try this:

import string

l = list(string.ascii_lowercase)

new_letters = {a:l[(i+13)%26] for i, a in enumerate(l)}

Alpha = input("Input the word you would like translated")

print(''.join(new_letters[i] for i in Alpha))

Answer 3

I think you want this

import string

inputchar = input('Enter input: ')
printables = [x for x in string.ascii_lowercase]
index = (printables.index(inputchar) + 13)%26
print(printables[index])