Flask provides a template engine is Jinja2, easy to use and powerful.
Template is just a text file that can generate any text-based format (HTML, XML, CSV, LaTex and so on).
It is not a specific extension, .html, or .xml are possible.
Template contains variable or expression, both of which will be replaced with values when the template evaluation. There is also a template tag, the control logic templates.
Jinja2 document: http: //docs.jinkan.org/docs/jinja2/index.html
Here are some use cases involving template continues, variable assignments, loops, go blank, escaped block, conditional statements and so on.
1, create a basic template files in the directory templates below base.html
<!doctype html>
<html>
<head>
<title>{{title}}</title>
<style text="text/css">
ul{list-style:none}
li{padding-left:20px}
</style>
</head>
<body>
<div id="content">
<h4>子模板内容</h4>
{% block content %}
{% endblock %}
</div>
</body>
</html>
2, also create a sub-template files in the directory templates below test1.html
{% extends 'base.html' %}
{# 这里是注释,上面标签表示当前模板继承自模板base.html #}
{% block content %}
变量:{{v1}}
<br />
赋值:
{% set v2 = 100 %}
{{v2}}
<br />
循环:
{% for item in items%}
{{ item.name }}
{% endfor %}
<br />
去空白:
{% for item in items -%}
{{ item.name }}
{%- endfor %}
<br />
转义块:
{% raw %}
<ul>
{% for item in list -%}
<li>{{ item }}</li>
{%- endfor %}
</ul>
{% endraw %}
条件语句:
{% for item in items%}
{% if item.name == '张三' %} {{item.name}}(管理员)
{% else %} {{item.name}}
{% endif %}
{% endfor %}
<br />
<form method="post" action="/getFormValue">
<input type="text" name="username" width="60" />
<input type="submit" value="获取表单值" />
</form>
{% endblock %}
3. Create test1.py catalog templates on the same level directory
from flask import Flask, render_template, request
app = Flask(__name__)
@app.route('/test1')
def test1() -> 'html':
items = [{'name':'张三'},
{'name':'李四'},
{'name':'王五'}]
return render_template('test1.html',
title='test',
v1='变量值',
items = items)
@app.route('/getFormValue', methods=['POST'])
def getFormValue() -> 'str':
username = request.form['username']
return username
app.run(debug = True)
4, execution py -3 test1.py at the command prompt
to access http://127.0.0.1:5000/test1, the page appears as follows:
子模板内容
变量:变量值
赋值: 100
循环: 张三 李四 王五
去空白: 张三李四王五
转义块:
{% for item in list -%}
{{ item }}
{%- endfor %}
条件语句: 张三(管理员) 李四 王五