1、變量標籤:{{變量}}
<html><body>{{ now }}</body></html>
2、for循環標籤:{% for item in list %},{% endfor %}
<ul>
{% for item in list %}
<li>{{ item }}</li>
{% endfor %}
</ul>
3、if-else分支標籤:{% If %},{% else %},{% endif %}
{% if true %}
<p> it is atrue part.</p>
{% else %}
<p> it is a false part.</p>
{% endif %}