using System;
using System.Text;
using System.IO;
using System.Net.Sockets;

namespace ConsoleApp01
{
    class Program
    {
        public static void Main(string[] args)
        {
             TcpClient client = new TcpClient("python.org",80);
             NetworkStream ns = client.GetStream();
             StreamWriter sw = new StreamWriter(ns);
             sw.Write("HEAD / HTTP/1.1\r\n"
             + "User-Agent: Test\r\n"
             + "Host: www.python.org\r\n"
             + "Connection: Close\r\n");
             sw.Flush();



            Console.ReadKey(true);
        }
    }
}

System.Net.Sockets.SocketException: Unable to make a connection because
the target machine actively refused it at System.Net.Sockets.TcpClient..ctor at ConsoleApp01.Program.Main :line 12

Why do i get this error message?