如何在不终止子进程的情况下在被调用的进程中使用子进程的输出? [英] How to use output of childprocess in called process without terminating child process?

问题描述

我已经在python中创建了两个模块.其中一个模块用于使用Tkinter创建GUI，第二个模块用于捕获和存储图像.当我在Tkinter模块中调用opencv模块时，它首先运行opencv模块，释放相机后，它正在运行Tkinter模块.因此，我使用了子进程. Popen().现在我想将子流程的输出输出到Tkinter模块中.使用Tkinter创建GUI的代码如下.

I have created two modules in python. One of the module is for creating GUI using Tkinter and second one is for capturing and storing images.When I called opencv module in Tkinter module,it runs opencv module first and after releasing camera,it was running Tkinter module.So I used subprocess.Popen(). Now I want output of subprocess into Tkinter module. The code for creating GUI using Tkinter is as follows.

import sys
from Tkinter import *
import Tkinter
import subprocess
def capcam():
    command="python2 imacap.py"
    subprocess.Popen(command,shell=True)
root=Tk()
add=Frame(root)
add.grid()
root.title("Test")
capcam()
button_height=11
button_width=29
button_ipadx=2
button_ipady=2
text_box = Entry(add,justify=RIGHT,width=100, font=100)
text_box.grid(row = 0, column = 1,columnspan = 5)
text_box.insert(0, "0")
bttn_3 = Button(add, height= button_height ,width= button_width,text = "3")
bttn_3.grid(row = 3, column = 2, padx=button_ipadx, pady=button_ipady)

以下是子进程的代码.

import cv2.cv as cv
capture = cv.CaptureFromCAM(0)
num = 0
while True:
    img = cv.QueryFrame(capture)
    cv.SaveImage('pic'+str(num)+'.jpg', img)
    if num == 500:
        del(capture)
        break
    if cv.WaitKey(10) == 27:
        break
    num += 1

我希望在mainprocess的运行时提供num变量的值，并希望将其传递给条目而不终止子进程.

I want the value of num variable at runtime in mainprocess and want to pass it to entry without terminating child process.

推荐答案

完整的代码示例: tkinter-read-async-subprocess-output.py 演示了如何在不使用线程的情况下读取子流程输出Tkinter.它在GUI中显示输出，并在按下按钮时停止子进程.

The complete code example: tkinter-read-async-subprocess-output.py demonstrates how to read the subprocess output without threads using Tkinter. It shows the output in the GUI and stops the subprocess on a button press.

如果tk.createfilehandler()在您的系统上不起作用；您可以尝试使用后台线程代替.有关代码示例，请参见 kill-process.py .

If tk.createfilehandler() doesn't work on your system; you could try to use a background thread instead. See kill-process.py for the code example.

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