I been using python to create an web app and it has been doing well so far. Now I would like to encrypt the transmission of the data between client and server using https. The communication is generally just post form and web pages, no money transactions are involve.  Is there anything I need to change to the python code except setting the server up with certificate and configurate it to use https? I see a lot of information regarding ssl for python and I not sure if I need those modules and python setup to make https work. 
Thanks
Typically, the ssl part for Python web app is managed by some frontend web server like nginx, apache or so.
This does not require any modification of your code (assuming, you are not expecting user to authenticate by ssl certificate on client side, what is quite exotic, but possible scenario).
If you want to run pure Python solution, I would recommend using cherrypy, which is able providing rather reliable and performant web server part (it will be very likely slower then served behind nginx or apache).
Is there any thing needed for https python web page