通过C＃脚本运行Python应用程序并与之交互

Question

I'm trying to use Unity C# (don't worry, easy to port to normal C# but I don't currently have a program that lets me do so) to run a python application using the following code, which basically just starts a python program and reads and writes some input and output:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

using System;
using System.Diagnostics;
using System.IO;
 using System.Text;

public class PythonSetup : MonoBehaviour {

    // Use this for initialization
    void Start () {
        SetupPython ();
    }

    void SetupPython() {
        string fileName = @"C:\sample_script.py";

        Process p = new Process();
        p.StartInfo = new ProcessStartInfo(pythonExe, "YOUR PYTHON3 PATH")
        {
            RedirectStandardOutput = true,
            UseShellExecute = false,
            CreateNoWindow = true
        };

        p.Start();

        UnityEngine.Debug.Log (p.StandardOutput.ReadToEnd ());
        p.StandardInput.WriteLine ("\n hi \n");
        UnityEngine.Debug.Log(p.StandardOutput.ReadToEnd());

        p.WaitForExit();
    }
}

The python application, located at C:/sample_script.py, is:

print("Input here:")
i = input()
print(i)

The C# program gives me the error:

InvalidOperationException: Standard input has not been redirected System.Diagnostics.Process.get_StandardInput () (wrapper remoting-invoke-with-check) System.Diagnostics.Process:get_StandardInput ()

Thanks for the help ahead of time!

To put into normal C# project, just replace UnityEngine.Debug.Log with Console.WriteLine and replace Start() with Main().

Answer 1

You need to configure your process so it knows to redirect input from the Standard Input stream and to your target application. Read more about this here .

Pretty much just amounts to including another property initialiser in your ProcessStartInfo :

    p.StartInfo = new ProcessStartInfo(pythonExe, "YOUR PYTHON3 PATH")
    {
        //You need to set this property to true if you intend to write to StandardInput.
        RedirectStandardInput = true,
        RedirectStandardOutput = true,
        UseShellExecute = false,
        CreateNoWindow = true
    };