How to select a specific area of ​​the screen in python and get its coordinates?

Question

Python

No code)
The bottom line is that there is a desire to do something similar to lightshot but with the ability to send it to your dropbox, google drive, ftp for storage.
The question arose of how to select a screen area, which library to use for this
Oh yes, I'm interested in a cross-platform library because it is supposed to be used on poppy and wine