fail_safe.py

from cryptography.fernet import Fernet


def write_key():
    key = Fernet.generate_key()
    with open("key.key", "wb") as key_file:
        key_file.write(key)


def load_key(name = 'key.key'):
    return open(name, "rb").read()


def encrypt(filename, key):
    f = Fernet(key)
    with open(filename, "rb") as file:
        # read all file data
        file_data = file.read()
    # encrypt data
    encrypted_data = f.encrypt(file_data)
    # write the encrypted file
    with open(filename, "wb") as file:
        file.write(encrypted_data)


def decrypt(filename, key):
    f = Fernet(key)
    with open(filename, "rb") as file:
        # read the encrypted data
        encrypted_data = file.read()
    # decrypt data
    decrypted_data = f.decrypt(encrypted_data)
    # write the original file
    with open(filename, "wb") as file:
        file.write(decrypted_data)

key = load_key("D:\key.key")
filename = input("what file do you want to encrypt/decrypt? Please include the file extension: ")
if input("do you want to encrypt or decrpyt(e/d): ") == 'e':
    encrypt(filename, key)
else: decrypt(filename, key)