Неизвестная синтаксическая ошибка

import os
import configparser
import dearpygui.dearpygui as dpg
config = configparser.ConfigParser()
def savecfg():
    config['main'] = {'checkbox': dpg.get_value('checkbox'),
    'slider': dpg.get_value('slider')}
    print("SAVED!")
    with open('config.ini', 'w') as configfile:
          config.write(configfile)
 
def loadcfg():
    config.read('config.ini')
    
    if (config['main']['checkbox']) == 'True':
        dpg.set_value("checkbox", True)
    else:
        dpg.set_value("checkbox", False)
 
    dpg.set_value("slider",config['main']['slider'])
    print('LOADED!')
 
def start_threads():
    try:
        menu()
        dpg.set_item_callback('savecfg_button', savecfg)
        dpg.set_item_callback('loadcfg_button', loadcfg)
    except Exception as err:
        print(f'Threads have been canceled! Exiting...\nReason: {err}\nExiting...')
        os._exit(0)
 
def menu(self):
        dpg.create_context()
        dpg.create_viewport(title=self, decorated=True, min_width=425, min_height=620, width=430, height=640)
        dpg.setup_dearpygui()
 
        with dpg.window(label='Menu', tag='menu', min_size=[425, 620], no_close=True, no_move=True, no_title_bar=True, horizontal_scrollbar=True):
            with dpg.collapsing_header(label="fancy menu", tag='fancy_menu_header'):
                dpg.add_checkbox(label='this is a checkbox', tag='checkbox')
                dpg.add_slider_float(label='and this is a slider', default_value=0.0, min_value=0.0, max_value=5.0, width=215, tag='slider')
                dpg.add_button(label='Safe config to cfg.ini', width=300, height=30, tag='savecfg_button')
                dpg.add_button(label='load config from cfg.ini', width=300, height=30, tag='loadcfg_button')
 
 
start_threads()
dpg.start_dearpygui()