How to build web flow in python?

I am administering online surveys for discounts. I am using a web based tool similar to survey monkey.

I have a python script that is reads in a json file of survey results. From here based on a randomizer issues a win or lose, if you win you get the discount, if lose you get nothing.

I am wanting to have a designer create a beautiful webpage and I want to launch the website if you win in the same browser window that the survey is being taken in.

How would I do this?

The flow of the website is:

website URL for the survey displayed -> take survey and hit submit -> python script parses and selects winner/loser -> if winner, display website of winner page -> reset page back to URL of survey