rotCipher.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
# =============================
# Author	--> DevMen
# Date created	--> 07/04/2021
# Last modified	--> 20/10/2023
# Version	--> Python 3.11.2
# =============================
'''
 Este programa fue echo para aplicar
 encriptacion ROT/caesar cipher
'''
# =============================
# Imports
import argparse
# =============================
# For example, ROT 13 would be:
# Index		0|1 |2 |3 |4 |5 |6 |7 |8 |9 |10|11|12|13|14|15|16|17|18|19|20|21|22|23|24|25
# English	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
# ROT+13	n|o |p |q |r |s |t |u |v |w |x |y |z |a |b |c |d |e |f |g |h |i |j |k |l |m

ALPHABET = [
    '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'
]


def banner():
    return """
   ___       __        _      __          
  / _ \___  / /_  ____(_)__  / /  ___ ____
 / , _/ _ \/ __/ / __/ / _ \/ _ \/ -_) __/
/_/|_|\___/\__/  \__/_/ .__/_//_/\__/_/   
                     /_/                  
_________________________by ☆ developmentMen☆
"""


def generateKey(rotNum):
    key = {}
    for i, ch in enumerate(ALPHABET):
        if (i + int(rotNum)) < len(ALPHABET):
            key[ch] = ALPHABET[i + int(rotNum)]
        else:
            key[ch] = ALPHABET[(i + int(rotNum)) % len(ALPHABET)]
    return (key)


def encrypt(normalStr, key):
    encryptedText = ''
    for word in normalStr.split(' '):
        encryptedText += ' '
        for ch in word:
            if ch in key:
                encryptedText += key[ch]
            elif ch.lower() in key:
                encryptedText += key[ch.lower()].upper()
            else:
                encryptedText += ch
    return (encryptedText)


def guardar(fileName, encryptedText):
    with open(fileName, "a") as f:
        f.write(encryptedText)


def main(s, n, f):
    outputFile = ""
    outputFile += encrypt(s, generateKey(n))+'\n\n'
    print('========= Rotation {} =========='.format(n))
    print('\t'+encrypt(s, generateKey(n)))
    if f != 'no save':
        if f[-4:] != '.txt':
            f += '.txt'
        guardar(f, outputFile)
        print("saved as {}".format(f))


if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="a simple Rot cipher")
    parser.add_argument('-nb', '--noBanner',
                        action='store_true', help='no print banner')
    parser.add_argument('-s', '--string', type=str,
                        metavar='', help='string to encode/decode')
    parser.add_argument('-n', '--number', type=int, default=13,
                        metavar='', help='numbers of rotations')
    parser.add_argument('-o', '--output', type=str, metavar='',
                        help="save the output as .txt file", default="no save")

    args = parser.parse_args()

    if not args.noBanner:
        print(banner())
    try:
        main(args.string, args.number, args.output)
    except Exception as a:
        print("============ ERROR ============")
        print("\n======== {} ======== \n\n\tpls select the string tho encrypt whit -s or --string\n".format(a))