how many Programming languages does GD sport? 
If you mean the development of Gdevelop, I have not checked the code and can be wrong. But I think it uses C++ and Javascript.
If you mean usage of Gdevelop, well, you can use the Gdevelop “code” (events and actions), write custom cpp additions in native platform mode, and also write custom javascript code in HTML 5 games.
Does it sport Python? Can I create a game using GD and python?
Not easily. What were you planning to write in python though? There is a high chance you can do it within GD.
Almost not possible, Python is cool, but GD event system is easy as Python, maybe not so powerful.
You could try JavaSscript, with my knowledge of Python and googling a bit I made some JavaScript examples pretty easy 
Thanks!