try: from Crypto.Cipher import AES aes = AES.new except ImportError: try: from cryptolib import aes except ImportError: print("SKIP") raise SystemExit crypto = aes(b"1234" * 4, 2, b"5678" * 4) enc = crypto.encrypt(bytes(range(32))) print(enc) crypto = aes(b"1234" * 4, 2, b"5678" * 4) print(crypto.decrypt(enc))