How do I run python script within swift app?
Short answer: You don't. 
There is no Python interpreter running on iOS, and Apple will likely neither provide nor allow one, since they don't allow you to deliver and run new code to in iOS app once it's installed. The code is supposed to be fixed at install time, and Python is an interpreted language.
I am making an app which will login to a website and scrape the website for the information I have. I currently have the all the login and web scraping written in Python completely done. What I am trying to figure out is running that python code in Xcode in my swift project. I want to avoid setting up a server capable of executing cgi scripts. Essentially the user will input their credentials and I will pass that to the python file, and the script will run.