将 Python 作为子进程调用时，是否可以强制它以交互模式运行? [英] When calling Python as a subprocess, can I force it to run in interactive mode?

问题描述

我在使用 Scala 的 Mac 上，我想创建一个 Python 解释器作为我的程序与之交互的子进程.我一直在使用 Process 和 ProcessIO，但 python 坚持在非交互模式下运行.因此，它只会在我关闭其输入并终止进程后执行任何操作.有没有办法强制它以交互模式运行，以便我可以保持 Python 进程的活动状态并与之交互?此示例代码(我将其粘贴到 Scala repl 中)显示了问题:

I'm on a mac using Scala, and I want to create a Python interpreter as a subprocess that my program interacts with. I've been using Process with a ProcessIO, but python insists on running in non-interactive mode. So it only does anything after I close down its input and kill the process. Is there a way to force it to run in interactive mode, so that I can keep the Python process alive and interact with it? This sample code (which I'm pasting into a Scala repl) shows the problem:

import scala.sys.process._
import scala.io._
import java.io._
import scala.concurrent._
val inputStream = new SyncVar[OutputStream];
val process = Process("python").run(pio)
val pio = new ProcessIO(
    (stdin: OutputStream) => {
        inputStream.put(stdin)
    },
    (stdout: InputStream) => {
        while (true) {
            if (stdout.available > 0){
                Source.fromInputStream(stdout).getLines.foreach(println)
            }
        }
    },
    stderr => Source.fromInputStream(stderr).getLines.foreach(println),
    daemonizeThreads=true
    )
def write(s: String): Unit = {
    inputStream.get.write((s + "\n").getBytes)
    inputStream.get.flush()
}
def close(): Unit = {
    inputStream.get.close
}
write("import sys")
write("try: print 'ps1:', sys.ps1")
write("except: print 'no ps1'")
close  // it's only here that output prints to the screen

推荐答案

使用 -i 标志调用 Python.

Invoke Python with the -i flag.

当未指定脚本时，这会导致 Python 以交互模式运行，无论 stdin 是否显示为终端.当指定脚本时，这会导致 Python 在执行脚本后进入交互模式.

When no script is specified, this causes Python to run in interactive mode whether or not stdin appears to be a terminal. When a script is specified, this causes Python to enter interactive mode after executing the script.

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