Python3: Decode ROT13-Encoded String: regex, ord(), chr()

decode-rot13.py

#!/bin/python3
'''Decode picoGym flag based on ROT13 cypher.'''
import re


def decode_rot13(s: str) -> str:
    '''Decode string.'''
    decode = ''
    for char in s:
        if ord(char) > 64 and ord(char) < 78:
            decode += chr(ord(char) + 13)
        elif ord(char) > 77 and ord(char) < 91:
            decode += chr(ord(char) - 13)
        elif ord(char) > 96 and ord(char) < 110:
            decode += chr(ord(char) + 13)
        elif ord(char) > 109 and ord(char) < 123:
            decode += chr(ord(char) - 13)
        else:
            decode += char
    return f'\x1b[44mDecoded string\x1b[0m: {decode}'


if __name__ == '__main__':
    print(decode_rot13(input('\x1b[44mPaste encoded string\x1b[0m: ')))

The ROT13 flips letters of the alphabet half-wise. <-- I know, that's vague.

A B C D E F G H I J K L M 
N O P Q R S T U V W X Y Z

HELLO WORLD becomes URYYB JBEYQ