After reading through a bunch of stuff, I am still not clear on this question. I am leaning towards: No, there is only Java, or C++. But there seems to be a lot of confusion in the public domain over this topic. You get plenty of hits for using Python in LibreOffice Calc, but all I want to do is write into the two-dimensional grid of a spreadsheet from an EXISTING Python application. So technically speaking, I want to use LibreOffice in Python, not the other way around. Incidentally, I do not use Windows.
I will start with a comment, or better a question:
Do you want to “use” LibreOffice, and write in an active grid, visible on the screen like an actual user? Or is all you need a possibility to save the data of your python program as a spreadsheet, especially an odc-file?
As you may see in this answer
it is possible to start LibreOffice so that you can communicate with the program/uno-API via a port. This (german) article use this for automated reports.
and here you find an question on this ask-site:
Thank you. The references are helpful.