How can I see what exceptions my IronPython script is generating?

Question

I am experimenting with embedding IronPython in a Unity 3D project and I've run into some errors I can't seem to figure out.

I have the following script attached to a GameObject in Unity.

using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEditor;
using IronPython;
using IronPython.Modules;
using System.Text;

public class IronPythonWrapper : MonoBehaviour {

    void Start() {
        ScriptTest();
    }

    public static void ScriptTest() {
        // create the engine
        var engine = IronPython.Hosting.Python.CreateEngine();

        // and the scope (i.e. the Python namespace)
        var scope = engine.CreateScope();

        // execute the Python script
        engine.ExecuteFile("Assets/Scripts/ipscript.py");

        // grab the variable from the Python scope
        string commands = scope.GetVariable<string>("commands");
        Debug.Log(commands);
    }
}

The goal is to have the IronPython engine instantiated above execute the following simple Python script, called ipscript.py .

commands = "Script executed."

When I enter play mode (in Unity) I get the following error.

MissingMemberException: 'ScopeStorage' object has no attribute 'commands'

Does anyone have any idea what I should investigate to resolve this problem? Perhaps I need to implement some error trapping so I can see any exceptions IronPython is generating when it executes the Python script?

Answer 1

Your python execution is not properly passing the scope. Your commands variable is therefore created on a transient scope that is discarded after executing the python file and the explicitly created scope has no idea what commands is.

The snippet should read like

engine.ExecuteFile("Assets/Scripts/ipscript.py", scope);