python string encryption, decryption - example code

from cryptography.fernet import Fernet

def encrypt(message: bytes, key: bytes):
    return Fernet(key).encrypt(message)

def decrypt(token: bytes, key: bytes):
    return Fernet(key).decrypt(token)

key = Fernet.generate_key()  # store in a secure location
#ex) key is 'Fn1dPza4Gchl7KpPE4kz2oJEMFXYG39ykpSLcsT1icU='

message = 'This is scret string'
#encryption
enstr = encrypt(message.encode(), key)
#decryption
destr = decrypt(enstr, key).decode()

print('input:',  message)
print('encryption:', enstr)
print('decryption:', destr)