16 byte key using a public key in aes python code example

Example 1: pycryptodome rsa encrypt

>>> from Crypto.Cipher import PKCS1_v1_5
>>> from Crypto.PublicKey import RSA
>>> from Crypto.Hash import SHA
>>>
>>> message = b'To be encrypted'
>>> h = SHA.new(message)
>>>
>>> key = RSA.importKey(open('pubkey.der').read())
>>> cipher = PKCS1_v1_5.new(key)
>>> ciphertext = cipher.encrypt(message+h.digest())

Example 2: pycryptodome rsa encrypt

from Crypto.Cipher import AES
from Crypto.Random import get_random_bytes

key = get_random_bytes(16)
cipher = AES.new(key, AES.MODE_EAX)
ciphertext, tag = cipher.encrypt_and_digest(data)

file_out = open("encrypted.bin", "wb")
[ file_out.write(x) for x in (cipher.nonce, tag, ciphertext) ]
file_out.close()