Pass session information from php to python securely? (in agile)

Question

I have a sign up process that is in a legacy framework and we are trying to switch to a new framework...in fact a different language. So let's say that there are 3 steps in the sign up process and each of those 3 steps has it's own file(step1.php, step2.php, step3.php).
Now if I want to change page2.php to a python file I will still need the session information from page1.php. How can I transfer this information between the two pages while maintaining a valid session and obviously security.

We want to integrate this language switch in the same repository as the original one and doing releases of the new changes. So that's the agile part. (I'm still not sold that this is the best way to do it but I'm more curious)

Answer 1

In PHP, store the session information in a database, encoded in JSON. In Python, pull the session ID from the cookie and look up the session information in the database.