django:我可以在 html 模板中编写 python 吗？

Question

{% if request.session["user_name"] %}
<div class="abcd">user has username</div>
{% else %}
<div class="abcd">user doesn't has username</div>
{% endif %}

这是违法的吗？有错误:

TemplateSyntaxError at /users/register/submit

Could not parse the remainder: '['user_name']' from 'request.session['user_name']'

Answer 1

Django 文档说:

Django template system is not simply Python embedded into HTML

这意味着您不能编写 Python。

但是谈论变量，doc还说:

Behind the scenes

Technically, when the template system encounters a dot, it tries the following lookups, in this order:

• Dictionary lookup
• Attribute lookup
• Method call
• List-index lookup

这意味着您正在尝试的是可能的，但正确的语法是:

{% if request.session.user_name %}