Python Encryption Code

from Crypto.PublicKey import RSA
from Crypto import Random

def rsa_keygen():
    global key
    random_generator = Random.new().read
    key = RSA.generate(2048, random_generator)
    return key

def encryption(config_data):
    global encrypted_config
    public_key = key.publickey()
    encrypted_config = public_key.encrypt(str(config_data), 32)

def decryption(data):
    global decrypted_config
    decrypted_config = key.decrypt(str(data))
    return decrypted_config

def main():


    rsa_keygen()


    #create a file first
    f=open('abc.txt','w')
    data='abcabcabc'
    f.writelines(data)
    f.close()

    f=open('abc.txt','r')
    adata=f.read()
    f.close()


    encryption(adata)

    #write the encryption binary back into abc.txt so that no one understand what abc contains.
    f=open('abc.txt','wb')
    f.write(encrypted_config[0])
    f.close()

    #open file again for decrypting
    f=open('abc.txt','rb')
    dedata=f.read()
    f.close()

    decryption(dedata)

    #write back the decrypted message into abc.txt
    f=open('abc.txt','w')
    f.write(decrypted_config)
    f.close()



main()