Migrate Halcon code to OpenCV
It depends on which Halcon functionalities are you using and why you want to do it. The question appears to be very general. I would recommend you to convert your Halcon Program to C++ and write a wrapper function to pass arguments to/from your openCV program.This would be the simplest option to provide interaction between your opencv and halcon program. Hope it helps.
I am developing a solution using a comercial computer vision software called Halcon. I am thinking on migrating or convert my solution to OpenCV in Python. I will like to start developing my other computer vision solution in Halcon because the IDE is incredible, and them generate a script to migrate them to OpenCV.
Does anyone know any library for this task? 
I will like to start developing an open source SDK to convert Halcon to OpenCV. I and thinking to start developing all internal function from Halcon to Python. Any advice?