calling python from java

I need to call some Python code from Java.

I am aware though that Jython exists or that Java has its own Python interpreter.

Thing is, said Python code uses some native (C) compiled code, even runs something on GPU.

So I can divide this into two questions:

Does Jython or Java's Python interpreter support this? That is, the Python code (when called from Java) would run with all the C and GPU parts, thus will run roughly as fast as it would on its own.
If neither of the above mentioned ways support this, is there any other way to do this?

P.S. If that helps, although I suppose it's irrelevant, the code I need to run are highly GPU/C optimized neural networks from Keras (with TensorFlow underneath). I absolutely can't afford to run the only-Python interpreted version.

Solution

Currently jython does not support native compiled python modules. In order to run native modules you will need access to a native python(cpython) interpreter from java. There are several open source projects that use JNI to access a cpython interpreter. Three projects that you can look into are JEP, JPY, and JyNI. In regards to GPU access, I only have experience with JEP which I have used with PyCUDA to execute code on the GPU. While I don't have personal experience with tensorflow, I know there are posts on the JEP mailing list regarding using JEP and tensorflow so I believe there are other projects using this combination successfully.