IronPython and C# 4 "dynamic"

dynamic_demo.cs

using System;
using IronPython.Hosting;
        
public class dynamic_demo {
    static void Main() {      
        var ipy = Python.CreateRuntime();
        dynamic mock = ipy.UseFile("mock.py");
        
        // Calls the Python Mock type's constructor
        dynamic m = mock.Mock();
        
        //The Python Mock type dynamically implements any member that is requested of it
        System.Console.WriteLine(
            m.the_csharp_compiler_cannot_possbily_know_this_member_exists_at_compile_time
        );
    }
}

mock.py

import random, math

class Mock(object): 
    def __getattr__(self, key):
        """Mock objects of this type will dynamically implement any requested member"""
        return random.choice(["hello world", math.pi])