[Python] Send Data from [Python Client] to [C# Server] using Socket

I want to send byte data from Python-Client to C# Server using a simple Socket Application. The C# Server is working fine with a C# Client !

But when I try to use Python Socket to send data to the C#-Server, the data never arrives.

I'm not very used to Python, can someone check my Code and give me a hint how to receive the data in my c# Server?

Did I make a mistake in code? Is this maybe the wrong way to send byte data from Python to C#? Is there a better solution?

Python Client:

import socket

TCP_IP = '127.0.0.1'
TCP_PORT = 5005
MESSAGE = b'Hello World !'

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.connect((TCP_IP, TCP_PORT))
s.send(MESSAGE)
s.close()


C# Server:

private void start()
{
Console.WriteLine("Port: ");
_port = Console.ReadLine();
byte[] buffer = new Byte[1024];
IPEndPoint localEndPoint = new IPEndPoint(IPAddress.Parse("127.0.0.1"), int.Parse(_port));
Socket listener = new Socket(AddressFamily.InterNetwork, SocketType.Stream, ProtocolType.Tcp);

try
{
listener.Bind(localEndPoint);
listener.Listen(10);

while (true)
{
Console.WriteLine("Waiting for a connection...");
Socket socket = listener.Accept();
data = null;

while (true)
{
int bytesRec = socket.Receive(buffer);
data += Encoding.ASCII.GetString(buffer, 0, bytesRec);
if (data.IndexOf("<EOF>") > -1)
{
break;
}
}

Console.WriteLine("Text received : {0}", data);
byte[] msg = Encoding.ASCII.GetBytes(data);

socket.Send(msg);
socket.Shutdown(SocketShutdown.Both);
socket.Close();
}

}
catch (Exception e)
{
Console.WriteLine(e.ToString());
}

Console.WriteLine("\nPress ENTER to continue...");
Console.Read();
}

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