ROT5.py

# *********
# -*- Made by VoxelPixel
# -*- For YouTube Tutorial
# -*- https://github.com/VoxelPixel
# -*- Support me on Patreon: https://www.patreon.com/voxelpixel
# *********

import re
import sys


def cipher_encryption(rot5, zero_to_nine):
    message = input("Enter message: ")

    # checking if input is int or not
    if not re.search('[\d\s]+', message):
        print("Entered message is not an integer")
        sys.exit()
        # \d = int
        # \s = white space
        # + = one or more times
        # [] a set, with logical OR

    encryp_text = ""
    for i in range(len(message)):
        if message[i] == chr(32):
            encryp_text += " "
        else:
            for j in range(len(zero_to_nine)):
                # simple substitution
                if message[i] == zero_to_nine[j]:
                    encryp_text += rot5[j]
                # inner if
            # inner for
        # if-else
    # for

    print("Encrypted Text: {}".format(encryp_text))


def cipher_decryption(rot5, zero_to_nine):
    message = input("Enter message: ")

    # checking if input is int or not
    if not re.search('[\d\s]+', message):
        print("Entered message is not an integer")
        sys.exit()
        # \d = int
        # \s = white space
        # + = one or more times
        # [] a set, with logical OR

    decryp_text = ""
    for i in range(len(message)):
        if message[i] == chr(32):
            decryp_text += " "
        else:
            for j in range(len(zero_to_nine)):
                # simple substitution
                if message[i] == rot5[j]:
                    decryp_text += zero_to_nine[j]
                    # inner if
                    # inner for
                    # if-else
    # for

    print("Encrypted Text: {}".format(decryp_text))


def main():
    rot5 = "5678901234"
    zero_to_nine = "0123456789"

    choice = int(input("1. Encryption\n2. Decryption\nChoose(1,2): "))
    if choice == 1:
        print("---Encryption---")
        cipher_encryption(rot5, zero_to_nine)

    elif choice == 2:
        print("---Decryption---")
        cipher_decryption(rot5, zero_to_nine)

    else:
        print("Wrong Choice")

if __name__ == "__main__":
    main()