How to create a new console in Python to print message-CodePudding

I make a python script running in the console, and I want to create another console for printing important messages without running another python script to do that.
I first tried to use win32console.AllocConsole() directly, but it got Access is denied (Seemingly because one process can attach to at most one console according to the docs).
So I tried creating a new process by using multiprocessing :

import sys, os
import win32api, win32con, win32console
import multiprocessing

def ShowConsole():
    win32console.FreeConsole()
    win32console.AllocConsole()
    sys.stdout = open("CONOUT$", "w")
    sys.stderr = open("CONOUT$", "w")
    print("Test")
    os.system("pause")

if __name__ == '__main__':
    p = multiprocessing.Process(target=ShowConsole)
    p.start()

But when I ran the code in Powershell, it exited directly with no message while no new console is created.
None of the possible solutions I found in stackoverflow works for me. What should I do?

Update: It turns out that it is because multiprocessing.Process fails to call ShowConsole function. I use multiprocessing.dummy.Process as the alternative and it works as expected.
The reason why multiprocessing.Process fails to call target is still unclear.

CodePudding user response：

There's nothing wrong with your example above, it pops the console as shown below. I added a "hello" in the main section to differentiate.

But since you want to values from the first console to the second, here's a better example. Utilize put/get to pass the information from the first console to the second console.

import win32console
import multiprocessing
import time

def secondconsole(output):
    win32console.FreeConsole()
    win32console.AllocConsole()
    while True:
        print(output.get())

if __name__ == "__main__":
    output = multiprocessing.Queue()
    multiprocessing.Process(target=secondconsole, args=[output]).start()
    while True:
        print("Hello World")
        output.put("Hello to second console")  #here you will provide the data to the second console
        time.sleep(3)   #sleep for 3 seconds just for testing

CodePudding user response：

It looks like the issue might be with the way you are trying to open the console using sys.stdout and sys.stderr. Try using the following code instead:

import sys, os
import win32api, win32con, win32console
import multiprocessing

def ShowConsole():
    win32console.FreeConsole()
    win32console.AllocConsole()
    os.dup2(win32console.GetStdHandle(win32console.STD_OUTPUT_HANDLE), sys.stdout.fileno())
    os.dup2(win32console.GetStdHandle(win32console.STD_ERROR_HANDLE), sys.stderr.fileno())
    print("Test")
    os.system("pause")

if __name__ == '__main__':
    p = iprocessing.Process(target=ShowConsole)
    p.start()