How to embed python2 into python3?

[ytj]

Hello, all:

I have two programs, one is written in py3k, the other is written in
python 2. I am wondering how to make them work together except port
the python 2 code to py3k? Is that possible to expose python2's
function to py3k? In other words, I want to embed the Python 2
interpreter into my py3k program. So I can call python2's function in
py3k's code.

Regards,
Tianjiao