Rename id variable and mentions to id_

examples/tutorial/flaskr/templates/blog/update.html

@@ -13,7 +13,7 @@
     <input type="submit" value="Save">
   </form>
   <hr>
-  <form action="{{ url_for('blog.delete', id=post['id']) }}" method="post">
+  <form action="{{ url_for('blog.delete', id_=post['id']) }}" method="post">
     <input class="danger" type="submit" value="Delete" onclick="return confirm('Are you sure?');">
   </form>
 {% endblock %}