code: def failsafe(func):
      
  
      @functools.wraps(func)
      def wrapper(*args, **kwargs):
          extra_files = []
  
          try:
              return func(*args, **kwargs)
          except:
              exc_type, exc_val, exc_tb = sys.exc_info()
              traceback.print_exc()
  
          tb = exc_tb
          while tb:
              filename = tb.tb_frame.f_code.co_filename
              extra_files.append(filename)
              tb = tb.tb_next
  
          if isinstance(exc_val, SyntaxError):
              extra_files.append(exc_val.filename)
  
          app = _FailSafeFlask(extra_files)
          app.debug = True
  
          @app.route('/')
          @app.route('/<path:path>')
          def index(path='/'):
              reraise(exc_type, exc_val, exc_tb)
  
          return app
  
      return wrapper
docs: Wraps an app factory to provide a fallback in case of import errors.
  
      Takes a factory function to generate a Flask app. If there is an error
      creating the app, it will return a dummy app that just returns the Flask
      error page for the exception.
  
      This works with the Flask code reloader so that if the app fails during
      initialization it will still monitor those files for changes and reload
      the app.