base.html
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN">
<html lang="en">
<head>
<title>{% block title %}{% endblock %}</title>
</head>
<body>
<h1>My helpful timestamp site</h1>
{% block content %}{% endblock %}
{% block footer %}
<hr>
<p>Thanks for visiting my site.</p>
{% endblock %}
</body>
</html> {% extends "base.html" %}
{% block title %}The current time{% endblock %}
{% block content %}
<p>It is now {{ current_date }}.</p>
{% endblock %} 很不理解 这个东西 怎么就继承了呢？ base.html <title>{% block title %}{% endblock %}</title> 这么写是什么意思啊？
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
You can understand it this way
base.html is the master template
a.html is the child template
{% block title %}{% endblock %} You can understand it as a placeholder or variable
As long as your a.html page inherits bash.html with {% extends "base.html" %}
In a.html It contains all the content in base.html, and you can use {% block title %}abc{% endblock %} to modify the value of your subpage
You can study the source code implementation process. As for <title>{% block title %}{% endblock %}</title> here is a simple Update mechanism