How do I package a Python web scraper as a Chrome Extension?
You cannot. Chrome extensions are written in JS.
The only way to accomplish what you want is to use the extension as a bridge from users browser to your script. You'll need to convert the script into a server of some kind that can accept requests from the extension and respond.
I made an Amazon Web Scraper and I want it work as an extension. What will happen is that it will  display the price if it is lower than the previously recorded price. I don't know Javascript. I went through things like Transcrypt but didn't understand much