Caesar Cipher with brute force

Question

I am new to python. I wrote the following Caesar Cipher. Could someone help me to improve the code or make it shorter? Thanks in advance. PS. #COM is to make comments.

import os #COM
import pyperclip
import sys #COMMMMMMMMMMMMMM

#GETTING MODE
def get_mode():
    try:
        while True:
            print('Press "E" to encrypt\nPress "D" to decrypt') ##COM
            mode = input().lower()
            if mode == 'e':
                print('You have chosen to encrypt') ##COMMMMMM
                return mode
            elif mode == 'd':
                print('You have chosen to decrypt') ##COMMMMM
                return mode#COM
            elif mode == 'god mode': ## GOD MODE TO INITIATE BRUTE FORCE
                print('Initiating God Mode') #COMMMM
                return mode
            print('Invalid option selected') #COMMMMM
    except ValueError: #COM
        print('Invalid input')
        get_mode()

#GETTING SECRET KEY
def get_key():
    try:
        while True:
            print('Please select a secret key: ')
            key = int(input())
            if (key >= 1) and (key <= 26):
                return key
            print('Key has to be between 1-26')
    except ValueError:
        print('Key has to be an integer') #COM
        get_key()

#ALL CHARACTERS
def all_cha(): #COM
    all_characters = ''
    for i in range(1, 1000):
        all_characters += chr(i) #COMMMM
    return all_characters #COOOMMMMMMMMMMMMM

#INPUT MESSAGE
def get_message():
    print('Please enter the message here:') #COOOOOOOOOOO
    mess = input()
    return mess #COOOMMMMMMMMMMMMMM

#MAIN CIPHER
def caesar_cipher(mode, message, key): ##COM 
    result = ''
    for characters in message:
        if characters in all_cha():
            num = all_cha().find(characters)
            if mode == 'e': #COM
                num += key
            elif mode == 'd':
                num -= key
            result += all_cha()[num]
        else: #COM
            result += characters
    print('Your translated message is: ' + result.encode(sys.stdout.encoding, errors='replace').decode())  #COM
    pyperclip.copy(result)
    write_message(result)
    return str(result.encode(sys.stdout.encoding, errors='replace').decode())

#READ DATA FROM TEXT FILE
def read_message():
    with open(file_path, 'r', encoding='utf-8') as r:
        x = r.read()
        return x

#WRITE TO A TEXT FILE
def write_message(data): #COMMM ffff fffff
    with open(file_path, 'w+', encoding='utf-8') as f: #COOMMD ffff ffff
        f.write(str(data))

#BRUTE FORCE
def brute_force(message): #COOMMMMM
    empty = []
    print('All possible combinations are: \n')
    for i in range(1, 27):
        g = caesar_cipher('d', message, i)
        print(g)
        empty.append(g)
    write_message(empty)
    return str(empty)


def main():
    global file_name
    global file_path
    file_name = os.path.basename(sys.argv[0]) + '_encrypt.txt'
    file_path = os.path.join(os.path.expanduser('~'), 'Desktop', file_name)
    print('Welcome to PyCi_02 V1 by Aj')
    a, b, c = get_mode(), None, get_key()
    try:
        if a == 'e':
            b = get_message()
            caesar_cipher(a, b, c)
            os.system('pause')
        elif a == 'd' or a == 'god mode':
            if os.path.exists(file_path):
                b = read_message()
                if read_message() == '':
                    print('Need to write data to encrypt')
                    os.system('pause')
                else:
                    if a == 'god mode':
                        brute_force(b)
                        os.system('pause')
                    elif a == 'd':
                        caesar_cipher(a, b, c)
                        os.system('pause')
            else:
                print('No data file.. New file has been created.. Enter your message')
                x = input()
                write_message(x)
                b = read_message()
                if a == 'god mode':
                    brute_force(b)
                    os.system('pause')
                elif a == 'd':
                    caesar_cipher(a, b, c)
                    os.system('pause')
    except Exception:
        print('Something went wrong')
        main()

if __name__ == '__main__':
    main()

It is a basic Caesar cipher. I wanna make it shorter so, I was wondering if someone can give me feedback.

Answer 1

Comments

Remove the comments, they are not useful, they distract from the real code and make it more difficult to read.

• It's clear that you would comments on your code, so there is no need for the '#COM' comments.

• Comments like '#GETTING MODE' for a function named get_mode() does not add anything.

input

The input statement has a optional prompt argument so you can use:

mess = input('Please enter the message here:')

instead of:

print('Please enter the message here:') 
mess = input()

try except

Large try except blocks might be confusing for debugging, when the exception is raised you do not know exactly where the exception is raised. Furthermore I do not think the ValueError in get_mode is ever raised.

Recursion

In get_mode and get_key you call them self, although it works, this can be trickey. The while True: can do the same get_key can be rewritten to:

def get_key():
    while True: # until a good key is returned

        key_str = input('Please select a secret key(1-26): ')
        try:
            key = int(key_str)
        except ValueError:
            print('Please enter an integer')
            continue
        if (key >= 1) and (key <= 26):
            return key