It's worth repeating what others already said: Even for simple 90 degree rotations, you are never going to be able to do it anywhere near even the slowest C code in pure Python. You will have to use an external library written in C.

The single trick that comes to mind is using OpenGL for all your drawing, and uploading images as textures, and then just drawing them rotated. That would be fast in any language, but I am not sure if you can do this in Python.