Tkinter start/stop button for recording audio in Python

I am writing a program to record audio with the use of a Tkinter GUI. For recording audio itself, I use this code: https://gist.github.com/sloria/5693955 in nonblocking mode.

Now I want to implement something like a start/stop button, but feel like I am missing out on something. Following suppositions:

1. I can't use a while Truestatement either a time.sleep()function because it's going to break the Tkinter mainloop()

2. As a result, I will probably have to use a global bool to check whether my start_recording()function is running

3. I will have to call stop_recording in the same function as start_recordingbecause both have to use the same object

4. I can not use root.after() call because I want the recording to be user-defined.

Find a code snippet of the problem below:

import tkinter as tk
from tkinter import Button
import recorder

running = False

button_rec = Button(self, text='Aufnehmen', command=self.record)
button_rec.pack()

button_stop = Button(self, text='Stop', command=self.stop)
self.button_stop.pack()

rec = recorder.Recorder(channels=2)

def stop(self):
    self.running = False

def record(self):
    running = True
    if running:
        with self.rec.open('nonblocking.wav', 'wb') as file:
            file.start_recording()
            if self.running == False:
                file.stop_recording()

root = tk.Tk()
root.mainloop()

I know there has to be a loop somewhere, but I don't know where (and how).

Instead of with I would use normal

running = rec.open('nonblocking.wav', 'wb')

running.stop_recording()

so I would use it in two functions - start and stop - and I wouldn't need any loop for this.

I would need only global variable running to have access to recorder in both functions.

import tkinter as tk
import recorder

# --- functions ---

def start():
    global running

    if running is not None:
        print('already running')
    else:
        running = rec.open('nonblocking.wav', 'wb')
        running.start_recording()

def stop():
    global running

    if running is not None:
        running.stop_recording()
        running.close()
        running = None
    else:
        print('not running')

# --- main ---

rec = recorder.Recorder(channels=2)
running = None

root = tk.Tk()

button_rec = tk.Button(root, text='Start', command=start)
button_rec.pack()

button_stop = tk.Button(root, text='Stop', command=stop)
button_stop.pack()

root.mainloop()