django: Updating a database based on changes on a object or file?

Question

So I am making a website to dynamicaly calculate cost and profit of some crafts(bps) in a game (Eve btw). As I like to do calculations on my own and store my own data, I need to get most of the needed data from "Static Data Export" of the game. There is some API's and sql exports of the SDE but I dont like dependency on other people's work.

SDE is offered as a bunch of YAML files in a zip. I have a code to get the files out of zip and turn the YAML's into python dictionary and store as a pickle file.

Problem is said pickle files are thousands of dictionary items and takes quite a bit of time to go trough and check in database I made for them.

What can I do to compare previous update of SDE to current update of SDE and only update the changed parts in my database. Instead of going trough those thousands of items.

Is there a efficient way to compare and get a this parts changed output like git does or any other version control thingy out there and make use of it in python.

Even though I've been doing stuff with django over a few years. I never had to handle mass data and dont know efficient ways of doing it. I would appreciete every bit of tips and pointers.