Returning to previous volume level after Mute

[Windspar]

def mute():
    global prev_volume
    if mute_button['text'] == 'mute':
        # Get volume before setting it to zero
        prev_volume= pygame.mixer.music.get_volume()
        pygame.mixer.music.set_volume(0)
        mute_button['text'] = 'unmute'
 
    elif mute_button['text'] == 'unmute':
        pygame.mixer.music.set_volume(prev_volume)
        mute_button['text'] = 'mute'
    print(prev_volume)