Here are two projects that use JNI to connect the standard python interpreter into a JVM, both projects support python 3.

• JPy
• Jep

I would recommend starting with JPy since you currently have python and it allows you to call java from python.

How about using the Runtime.exec() method? Just do Process process = Runtime.getRuntime().exec("python script.py arg1 arg2"). Runtime is a class from the java.lang package, so you don't need to do any fancy import.

More info here.

EDIT

Ok, not too easy to manage if you have lots of functions. On the other hand if you don't mind a bunch of wrapper files just do a bit of code to build one automatically for each function.

Check out this little piece of Python code. Just replace foo with whatever your huge module is called, and you're good to go.

from inspect import getmembers, isfunction
import foo

f_list=[o[0] for o in getmembers(foo) if isfunction(o[1])]
for x in f_list:
    print("Build "+str(x))
    with open("helper_"+str(x)+".py","wt") as f:
        f.write("""import foo
import sys

arg_list=sys.argv[1::]
print(foo.{x}(*arg_list))""".format(x=x))