I need to encrypt a small string in Python. Is it possible to use a secret key to encrypt the string? Is there a good way to do this and achieve a reasonable encryption leve
KeyCzar has a nice interface and should meet your requirements. From the home page:
Keyczar is an open source cryptographic toolkit designed to make it easier and safer for devlopers to use cryptography in their applications. Keyczar supports authentication and encryption with both symmetric and asymmetric keys
crypter = Crypter.Read("/path/to/your/keys")
ciphertext = crypter.Encrypt("Secret message")