caesar.py

import string

def get_int(prompt, minimum, maximum):
    val = input(prompt)
    try:
        val = int(val)
    except ValueError:
        print("Please enter an int between {} and {}".format(minimum, maximum))
        return None
    else:
        return val

def trans_str_tbl(shift):
    #Lowercase
    low_alphabet = string.ascii_lowercase
    low_shifted_alphabet = low_alphabet[shift:] + low_alphabet[:shift]
    #Uppercase
    upper_alphabet = string.ascii_uppercase
    upper_shifted_alphabet = upper_alphabet[shift:] + upper_alphabet[:shift]
    #Make dictionary
    table = str.maketrans(low_alphabet, low_shifted_alphabet)
    table.update(str.maketrans(upper_alphabet, upper_shifted_alphabet))
    return table

def en_caesar(plaintext, key):
    table = trans_str_tbl(key)
    return plaintext.translate(table)

def de_caesar(ciphertext, key):
    table = trans_str_tbl(-key)
    return ciphertext.translate(table)

def force_caesar(ciphertext, wordlist):
    accuracy = {key: 0 for key in range(25)}
    result = {key: None for key in range(25)}
    for i in range(25):
        result[i] = de_caesar(ciphertext, i)
        
        for word in result[i].split():
            if word.lower() in wordlist.split():
                accuracy[i] += 1
        if accuracy[i] == len(result[i].split()):
            return result[i]  
    return result[list(accuracy.values()).index(max(list(accuracy.values())))]

if __name__ == "__main__":
    command = input("Do you want to 'decrypt', 'encrypt', or 'force'? ").lower().strip()
    if command == "encrypt":
        text = input("Enter the text to encrypt: ")
        while True:
            key = get_int("Enter the key, or shift, of the text (1-25): ", 0, 25)
            if key is not None:
                break
        print(en_caesar(text, key))
    elif command =="decrypt":
        text = input("Enter the text to decrypt: ")
        key = int(input("Enter the key, or shift, of the text (1-25): "))
        print(de_caesar(text, key))
    elif command == "force":
        wordlist = input("Wordlist path: ")
        print(force_caesar(input("Ciphertext: "), open(wordlist).read()))