Read command prompt output in new window in Python

Question

I referred to this Read Command Prompt output here. But I can't get it to work.

What I am trying to do is, I open a new command prompt window using subprocess.Popen and I want to run an exe file with some arguments. After I run that process, I want to capture the output or read the text in that command prompt.

When I say cmd = subprocess.Popen('cmd.exe /K "CoreServer.exe -c -s"',creationflags=CREATE_NEW_CONSOLE,shell=True,stdout=subprocess.PIPE) it won't run the process at all.

import subprocess
from subprocess import Popen, CREATE_NEW_CONSOLE

    def OpenServers():
            os.chdir(coreServerFullPath)
            cmd = subprocess.Popen('cmd.exe /K "CoreServer.exe -c -s"',creationflags=CREATE_NEW_CONSOLE)
            time.sleep(3)
            os.chdir(echoServerFullPath)
            #cmd.exe /K "EchoServer.exe -c -s"
            cmd1=subprocess.Popen('cmd.exe /K "EchoServer.exe -c -s"',creationflags=CREATE_NEW_CONSOLE)
            #subprocess.Popen(['runas', '/user:Administrator', '"CoreServer.exe -c -s"'],creationflags=CREATE_NEW_CONSOLE
            print("OUTPUT 1 "+cmd.stdout.readline())

Please see this screenshot, I want to read the text in the command prompt.

Just in case, here is the full code.

import os
import subprocess
from subprocess import Popen, CREATE_NEW_CONSOLE
import time
import ctypes, sys

#The command prompts must be opened as administrator. So need to run the python script with elebvated permissions. Or else it won't work
def is_admin():
    try:
        return ctypes.windll.shell32.IsUserAnAdmin()
    except:
        return False

if is_admin():
    #The program can only run with elevated admin previlages.
    
    #Get the directory where the file is residing.
    currentDirectory=os.path.dirname(os.path.abspath(__file__))
    coreServerFullPath=os.path.join(currentDirectory,"Core\CoreServer\Server\CoreServer/bin\Debug")
    isExistCoreServer=os.path.exists(coreServerFullPath)

    echoServerFullPath=os.path.join(currentDirectory,"Echo\Server\EchoServer/bin\Debug")
    isExistEchoServer=os.path.exists(echoServerFullPath)

    #For now this is the MSBuild.exe path. Later we can get this MSBuild.exe as a standalone and change the path.
    msBuildPath="C:\Program Files (x86)\Microsoft Visual Studio/2019\Professional\MSBuild\Current\Bin/amd64"
    pathOfCorecsProjFile=os.path.join(currentDirectory,"Core\CoreServer\Server\CoreServer\CoreServer.csproj")
    pathOfEchocsProjFile=os.path.join(currentDirectory,"Echo\Server\EchoServer\EchoServer.csproj")


    def OpenServers():
        os.chdir(coreServerFullPath)
        cmd = subprocess.Popen('cmd.exe /K "CoreServer.exe -c -s"',creationflags=CREATE_NEW_CONSOLE)
        time.sleep(3)
        os.chdir(echoServerFullPath)
        #cmd.exe /K "EchoServer.exe -c -s"
        cmd1=subprocess.Popen('cmd.exe /K "EchoServer.exe -c -s"',creationflags=CREATE_NEW_CONSOLE)
        #subprocess.Popen(['runas', '/user:Administrator', '"CoreServer.exe -c -s"'],creationflags=CREATE_NEW_CONSOLE
       



    if(not isExistCoreServer):
        if(os.path.isfile(pathOfCorecsProjFile)):
            os.chdir(msBuildPath)
            startCommand="start cmd /c"
            command="MSBuild.exe "+pathOfCorecsProjFile+" /t:build /p:configuration=Debug"
            #os.system(startCommand+command)
            cmd=subprocess.Popen(startCommand+command)

    if(not isExistEchoServer):
        if(os.path.isfile(pathOfEchocsProjFile)):
            os.chdir(msBuildPath)
            startCommand="start cmd /c"
            command="MSBuild.exe "+pathOfEchocsProjFile+" /t:build /p:configuration=Debug"
            os.system(startCommand+command)

    if(isExistCoreServer and isExistEchoServer):
        OpenServers()

else:
    # Re-run the program with admin rights
    ctypes.windll.shell32.ShellExecuteW(None, "runas", sys.executable, " ".join(sys.argv), None, 1)

Answer 1

Perhaps this might be what you are looking for: Running shell command and capturing the output

The answer there is very in depth, and I would recommend reading in full. To summarize:

Python 3.5+

If you are using Python 3.5+, then likely you want to use the run method in subprocess

import subprocess

result = subprocess.run(['CoreServer.exe', '-c', '-s'], stdout=subprocess.PIPE)
print(result.stdout)

Python 3-3.4

If you are using Python 3-3.4, then you will want to use the check_output method in subprocess

import subprocess

output = subprocess.check_output(['CoreServer.exe', '-c', '-s'])
print(output)