changing local variables in pyglet on_key_press

Question

I am a complete beginner in pyglet. I would like to have a local variable "state", and let certain events be executed only if the state is correct. This way, pyglet lets me write that label with on_text, but when I press backspace or enter it tells me that local variable "state" is referenced before assignment. It has something to do with that pyglet.window.key.TAB, because when I remove it, it works. What did I do wrong?

def run_application():
    window = pyglet.window.Window()
    
    state = "choose map" #in which "part" of the oplication we are right now
    racetrack_name = pyglet.text.Label("", x=10, y=20)
    print(state)
    
    @window.event
    def on_key_press(key_code, modifier):
        
        #OPEN menu
        if key_code == pyglet.window.key.TAB:
            state = "menu"
           
        #remove text when in "choose map"
        if key_code == pyglet.window.key.BACKSPACE and state == "choose map":
            racetrack_name.text = racetrack_name.text[:-1]
            
        elif key_code == pyglet.window.key.ENTER:
            if state == "choose map":
                print(racetrack_name)
            
    @window.event
    def on_text(text):
        if state == "choose map":
            racetrack_name.text = racetrack_name.text + text
  
    @window.event
    def on_draw():
        global state
        window.clear()
        racetrack_name.draw()
    
    pyglet.app.run()
    return

run_application()

Edit - full error traceback:

Exception ignored on calling ctypes callback function: <function Win32Window._get_window_proc.<locals>.f at 0x000001862D0644C0>
Traceback (most recent call last):
  File "C:\Users\ondra\AppData\Local\Programs\Python\Python39\lib\site-packages\pyglet\window\win32\__init__.py", line 747, in f
    result = event_handler(msg, wParam, lParam)
  File "C:\Users\ondra\AppData\Local\Programs\Python\Python39\lib\site-packages\pyglet\window\win32\__init__.py", line 819, in _event_key
    self.dispatch_event(ev, symbol, modifiers)
  File "C:\Users\ondra\AppData\Local\Programs\Python\Python39\lib\site-packages\pyglet\window\__init__.py", line 1352, in dispatch_event
    if EventDispatcher.dispatch_event(self, *args) != False:
  File "C:\Users\ondra\AppData\Local\Programs\Python\Python39\lib\site-packages\pyglet\event.py", line 408, in dispatch_event
    if handler(*args):
  File "C:\Users\ondra\AppData\Local\Temp\ipykernel_5256\3428602759.py", line 22, in on_key_press
UnboundLocalError: local variable 'state' referenced before assignment