Calling Python Functions from Java with Jython

Although Jython is primarily known for enabling Java calls from Python scripts, it also has the capability to bridge the gap in the opposite direction.

Using Jython to Call Python Functions

Jython acts as a bridge that allows Java applications to seamlessly invoke Python functions. To achieve this:

• Install Jython on your Java environment.
• Run Python scripts under Jython to ensure compatibility.
• Utilize Java's org.python.util.PythonInterpreter for Python script execution.

Example Implementation

To illustrate how Python functions can be called from Java using Jython, consider the following example:

PythonInterpreter interpreter = new PythonInterpreter();
interpreter.exec("import sys\nsys.path.append('pathToModules if they are not there by default')\nimport yourModule");
// Calling a Python function that takes a string and returns a string
PyObject someFunc = interpreter.get("funcName");
PyObject result = someFunc.__call__(new PyString("Test!"));
String realResult = (String) result.__tojava__(String.class);

Note on Python Version Support

It's important to note that as of 2021, Jython does not support Python 3.x. Therefore, ensure that your Python code meets these limitations for successful integration with Java.