code: def toggle_grid(self, evt=None, show=None):
          "toggle grid display"
          if show is None:
              show = not self.conf.show_grid
          self.conf.enable_grid(showf toggle_grid(self, evt=None, show=None):
          "toggle grid display"
          if show is None:
              show = not self.conf.show_grid
          self.conf.enable_grid(show)
docs: toggle grid display