C#からPythonプログラムを呼び出す（非同期対応）

SamplePythonAsyncCall.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Drawing;
using System.IO;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace TestUiPythonCall
{
    public partial class Form1 : Form
    {

        StreamWriter writer;
        int count = 0;

        public Form1()
        {
            InitializeComponent();

        }

        private void button1_Click(object sender, EventArgs e)
        {
            //テキストボックスの文字を渡す
            string text = textBox1.Text;
            writer.WriteLine(text);

        }

        private void Form1_Load(object sender, EventArgs e)
        {


            string fileName = @"C:\Users\ochi\Documents\temp\test.py";

            Process p = new Process();
            p.OutputDataReceived += new DataReceivedEventHandler(DataReceived);
            
            p.StartInfo.FileName = "python";
            p.StartInfo.Arguments = fileName;
            p.StartInfo.UseShellExecute = false;
            p.StartInfo.RedirectStandardOutput = true;
            p.StartInfo.RedirectStandardInput = true;
            p.StartInfo.CreateNoWindow = true;
            p.Start();
            p.BeginOutputReadLine();

            
            writer = p.StandardInput;
            writer.AutoFlush = true;


        }
        void DataReceived(object sender, DataReceivedEventArgs e)
        {
            //受け取った結果を表示する
            Console.WriteLine(e.Data);
        }
    }
}

test.py

while True:
    input_line1=input()
    print(input_line1+"from python",flush=True)