code: def render_alert(content, alert_type=None, dismissable=True):
      
      button = ""
      if not alert_type:
          alert_type = "info"
      css_classes = ["alert", "alert-" + text_value(alert_type)]
      if dismissable:
          css_classes.append("alert-dismissable")
          button = (
              '<button type="button" class="close" '
              + 'data-dismiss="alert" aria-hidden="true">&times;</button>'
          )
      button_placeholder = "__BUTTON__"
      return mark_safe(
          render_tag(
              "div",
              attrs={"class": " ".join(css_classes)},
              content=button_placeholder + text_value(content),
          ).replace(button_placeholder, button)
      )
docs: Render a Bootstrap alert