How to implement a system that will take data from the site?

Question

Parsing

How can I implement a system so that the program takes specific data from sites. For example, the number of graduates and dropouts, calculated the percentage of teachers with a degree and compared this data with a certain value.

Answer 1

Write a script in any of the common programming languages, implementing the given logic.
Or give it to freelance where they will do the same for money.

Answer 2

in Python

Answer 3

Selenium or injecting javascript code to stimulate user behavior and collect information using something like greasemonkey
Stimulating mouse clicks and copying the contents of divs is much easier than reverse engineering data transfer protocols with a backend