从单独的窗口python获取子进程的输出

Question

I am trying to write a program which lets the user select a variety of options which will contribute to a command that will run in a separate window in python. After this sub-process finishes, I would like it to exit and return whatever the output is for that particular command. Here is a snippet of my code:

if(fileName == "" or className == ""):
    tkMessageBox.showinfo("Error", "Please select a test class/test!")
else:
    command = "ctetest"
    if(verbose.get()):
        command += " -v"
    if(xml.get()):
        command += " -x"
    if(version.get()):
        command += " -V"
    if(output.get()):
        command += " -o"
    command += " RegressionTest/"
    command += folderName + " " + fileName + "." + className + "." + methodName
    processOutput = subprocess.Popen('start '+command, shell = True)
    processOutput.wait()
    processOutput.terminate()

The problem is that when the subprocess finishes, it just hangs there and I have to close it manually. Once I close it manually, it does not seem to generate any of the output produced by the subprocess. I have tried using

subprocess.check_output('start '+command, shell = True)

as well as

subprocess.popen('start '+command+' & exit', shell=True)

But same issue arises. The only work around I can think of is using threads but then how could I check if the subprocess is actually finish before I terminate it? Are there any other ways that I can accomplish this? Thanks in advance!

Answer 1

subprocess needs you to pass the arguments differently than what you're doing, you need to create a list that consists of the program to be run and it's arguments. For example ["ls", "-l", "/home"] .

So, your code would need to be this:

if(fileName == "" or className == ""):
    tkMessageBox.showinfo("Error", "Please select a test class/test!")
else:
    command = ["start ctetest"]
    if(verbose.get()):
        command.append("-v")
    if(xml.get()):
        command.append("-x")
    if(version.get()):
        command.append("-V")
    if(output.get()):
        command.append("-o")
    commandpath = "RegressionTest/" + folderName + " " + fileName + "." + className + "." + methodName
    command.append(commandpath)
    processOutput = subprocess.check_output(command, shell=True)

This creates the list of command and arguments with list.append() . It will automatically wait for the subprocess to finish and provide the entire output in the processOutput variable.