I am planning to write an simple 3d(isometric view) game in Java using jMonkeyEngine - nothing to fancy, I just want to learn something about OpenGL and writing efficient algorithms (random map generating ones). 
When I was planning what to do, I started wondering about switching to Python. I know that Python didn't come into existence to be a tool to write 3d games, but is it possible to write good looking games with this language? 
I have in mind 3d graphics, nice effects and free CPU time to power to rest of game engine? I had seen good looking java games - and too be honest, I was rather shocked when I saw level of detail achieved in Runescape HD. 
On the other hand, pygame.org has only 2d games, with some starting 3d projects. Are there any efficient 3d game engines for python? Is pyopengl the only alternative? Good looking games in python aren't popular or possible to achieve? 
I would be grateful for any information / feedback.
If you are worried about 3D performance: Most of the performance-critical parts will be handled by OpenGL (in a C library or even in hardware), so the language you use to drive it should not matter too much.
To really find out if performance is a problem, you'd have to try it. But there is no reason why it cannot work in principle.
At any rate, you could still optimize the critical parts, either in Python or by dropping to C. You still gain Python's benefit for most of the game engine which is less performance-critical.
Can 3D OpenGL game written in Python look good and run fast?