base.html【父页面】
<!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>
子页面
{% extends "base.html" %}
{% block title %}The current time{% endblock %}
{% block content %}
<p>It is now {{ current_date }}.</p>
{% endblock %}
子页面继承父页面,用子页面的块【block】覆盖父页面的块(子页面不重写则继承父页面内容),达到网站所有页面的相似性