How to open a Tkinter app from a PyQt GUI

Question

I have built an app with PySide2 (PyQt). Now I was asked to make a QPushButton, which simply starts an independent Tkinter app which someone else has programmed. I thought I could simply connect the method below to my QPushButton which starts the Tkinter App (Modell_final.App is the app):

def open_tkinter():
 root = tkinter.Tk()
 app = Modell_final.App(root)
 root.mainloop()

But when I push the Button inside my GUI the first time nothing happens and the second time the Tkinter App opens and freezes immediately. Thanks for help:)

Answer 1

I am not sure how independent the Tkinter app is. If it is truly just some other small window you want to run that eventually gets closed again I would opt for an own process for it.

You can try it like this. Please save it as "test_test.py"

import tkinter as tk
import subprocess

window = tk.Tk()
window.title("Window Title")
window.geometry('200x100')

lbl = tk.Label(window, text="Hello World")
lbl.pack()

def clicked(): #function before bind
    subprocess.Popen(['python' , 'test_test.py'])

btn = tk.Button(window, text="Click Me", command=clicked)
btn.pack()

window.mainloop()

If it is truly completly independet this would have the benefit that you do not even need to import the Modell_final into the PyQt app. Just import subprocess and let the button call the subprocesss.popen (not subprocesss.call , then it freezes again) python file with the tkinter app in it.

The downside is

1. Sharing data with the Tkinter app is difficult, but if it is independent no issue here.
2. If the button is pressed multiple times multiple windows of the Tkinter app open up. This might be what you want, but if not you have to take care of this.