Running multiple Kivy apps at same time that communicate with each other

Question

I would like my Kivy application to be able to spawn multiple apps (i.e. new windows) on a Windows machine that can communicate with each other.

ScreenManager and Po

Answer 1

bj0's answer regarding subprocess was correct.

Even better, I figured out how to do this via multiprocessing, which allows better communication and passing of information between apps. It wasn't working before because I did multiprocessing.Process(target=ChildApp().run()).start() when it should be multiprocessing.Process(target=ChildApp().run).start(). The following works

# filename: test.py

from kivy.app import App
from kivy.uix.button import Button

from test2 import ChildApp

import multiprocessing


class MainApp(App):

    def build(self):
        b = Button(text='Launch Child App')
        b.bind(on_press=self.launchChild)
        return b

    def launchChild(self, button):
        app = ChildApp()
        p = multiprocessing.Process(target=app.run)
        p.start()

if __name__ == '__main__':
    MainApp().run()

---

# filename: test2.py

from kivy.app import App
from kivy.uix.label import Label


class ChildApp(App):
    def build(self):
        return Label(text='Child')

if __name__ == '__main__':
    ChildApp().run()