Python as Scripting language for inline task

[saksham2105]

Pull Request type

• Bugfix
• Feature
• Refactoring (no functional changes, no api changes)
• Build related changes
• WHOSUSING.md
• Other (please describe):

NOTE: Please remember to run ./gradlew spotlessApply to fix any format violations.

Changes in this PR

Added Support for Python as scripting language for inline task using Jython library. Along with this there is a restriction for import keywords and various inbuilt functions for safety constraints. Added support for variable replacements for Simple ,Nested JSON types usin $.variable.variable2.... etc. Along with the Script expression in inputs map. We also have to add one more field in map named outputIdentifier: something

Use of outputIdentifier

Sample code :-

def add(a,b):
 return a + b
sum = add(1,2)
sum

In this case we will keep outputIdentifier: "sum" because this is the way we extract result of our Python code from Java using below snippet.

        String outputIdentifier = inputs.get("outputIdentifier").toString();
        PythonInterpreter interpreter = new PythonInterpreter();
        interpreter.exec(script);
        PyObject result = interpreter.get(outputIdentifier);

Roadmap : https://github.com/conductor-oss/conductor/blob/main/ROADMAP.md

---

Describe the new behavior from this PR, and why it's needed
Issue # New feature in OSS roadmap

Alternatives considered
We can also use GraalPy but it is super complex to setup

Describe alternative implementation you have considered

[izrail-p]

Hi @saksham2105
I’m having trouble returning a dictionary or list from my inline Python code. It works fine when I return a string, though. Any ideas on what might be going wrong?
Getting this error -
Suppressed: com.oracle.truffle.api.TruffleStackTrace$LazyStackTrace

[izrail-p]

@sauronmesh yes. I am using "evaluatorType": "python".

[saksham2105]

Hey @izrail-p no my ques is are you using jython or graal?

[saksham2105]

I think right now there is no such thing to support python as inline task

[izrail-p]

@saksham2105 I am using Jython.

[saksham2105]

imo it should be json serialized object and the object can have list or any other collection

[izrail-p]

if (input instanceof Map<?, ?>) { Map<String, Object> inputs = (Map<String, Object>) input; if (inputs.containsKey("evaluatorType") && inputs.get("evaluatorType").toString().equals("python")) { return evalPython(script, input);
@saksham2105 python is added here as evaluatorType right. I tried returning object as well.

[saksham2105]

I am not 100% About how to cast list and other data structure to jython PyObject

[aliakbar-nathani]

Are you looking into this to support of returning dictionary or a list from the inline python task ? Or is there any roadblock here?, since it is quite common usecase to return a dictionary from the inline script.