Solution IPTest
---Project IPTest
------Namespace IPTest
---------Program class (main)
---------Elem class
------Scripts
---------Worker.py

public class Elem {
    public string Name;
}

ScriptEngine engine = Python.CreateEngine();
ScriptSource source = engine.CreateScriptSourceFromFile("./Scripts/Worker.py");
ScriptScope scope = engine.CreateScope();
source.Execute(scope);
// or var worker = Python.CreateRuntime().UseFile("./Scripts/Worker.py");
dynamic Worker = scope.GetVariable("Worker");
dynamic worker = Worker();
var res1 = worker.add(4, 5);

import sys
import System
sys.path.append(System.IO.Directory.GetCurrentDirectory()) #make sure assembly dir is  in sys.path
import clr
clr.AddReference(“IPTest.exe”)
# or clr.AddReferenceToFile(r"IPTest.exe")
# or clr.AddReference(r"<fullpath>IPTestbinDebugIPTest.exe")
# or clr.AddReference(“../IPTest.exe”) #when not adding workingdir to sys.path
from IPTest import Elem
# or from IPTest.IPTest import Elem
# or import Elem

engine.Runtime.LoadAssembly(Assembly.GetExecutingAssembly()); //in c#
from IPTest import Elem # in python script