code: def url_rule(blueprint_or_app, rules,
               endpoint=None, view_func=None, **options):
      
      for rule in to_list(rules):
          blueprint_or_app.add_url_rule(rule,
                                        endpoint=endpoint,
                                        view_func=view_func,
                                        **options)
docs: Add one or more url rules to the given Flask blueprint or app.
  
      :param blueprint_or_app: Flask blueprint or app
      :param rules: a single rule string or a list of rules
      :param endpoint: endpoint
      :param view_func: view function
      :param options: other options