How to make a http request on newline progress output?

[Spoowy]

Hey guys!
I'm new to python and I just want to drop a handful of lines into the code so they will be executed whenever youtube-dl is outputting a new progress message line into the cmd.

I've looked into the files and found something like progress hooks but I wasn't sure where exactly to take a look at.
How can I make this happen? What are the files/lines of code I need to take a look at?

Thank you!
Erwin

[Spoowy]

I've found it! See > downloader > commons.py around line 215