Hosting IronPython 2

From IronPython Cookbook

The following C# code shows simple examples of using the IronPython 2 API to host IronPython in a .NET application. This code works with IronPython 2 beta 1.

using System;
using IronPython.Hosting;
using IronPython.Runtime;
using Microsoft.Scripting;
using Microsoft.Scripting.Hosting;

namespace EmbeddedCalculator
{
    public class Engine
    {
        private ScriptEngine engine;

        public Engine()
        {
            engine = PythonEngine.CurrentEngine;
        }

        public string calculate(string input)
        {
            try
            {
                ScriptSource source = engine.CreateScriptSourceFromString(input, "py");
                return source.Execute().ToString();
            }
            catch
            {
                return "Error";
            }
        }

    }
}

An alternative equivalent is:

    public class Engine
    {
        private ScriptEngine engine;
        private ScriptScope scope;

        public Engine()
        {
            engine = ScriptRuntime.Create().GetEngine("py");
            scope = engine.CreateScope();
        }

        public string calculate(string input)
        {
            try
            {
                ScriptSource source = engine.CreateScriptSourceFromString(input, SourceCodeKind.Expression);
                return source.Execute(scope).ToString();
            }
            catch
            {
                return "Error";
            }
        }

    }

For returning a known type from Execute we could use int result = source.Execute<int>(scope);.

Here's an example that sets some variables in the scope, executes some code, and then attempts to pull the variable 'x' back out of the scope:

    public class Engine
    {
        private object button;
        private ScriptEngine engine;
        private ScriptScope scope;

        public Engine()
        {
            engine = ScriptRuntime.Create().GetEngine("py");
            scope = engine.CreateScope();
        }

        public void set_button(object from_form)
        {
            button = from_form;
        }

        public string evaluate(string x, string code) 
        {
            scope.SetVariable("x", x);
            scope.SetVariable("button", button);

            try
            {
                ScriptSource source = engine.CreateScriptSourceFromString(code, SourceCodeKind.Statements);
                source.Execute(scope);
            }
            catch 
            {
                return "Error executing code";
            }

            if (!scope.VariableExists("x"))
            {
                return "x was deleted";
            }
            string result = scope.GetVariable<object>("x").ToString();
            return result;
        }
    }

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